referring in more detail to the drawings , fig1 a - 1b each show an assembly 10 , including a thermal protective sleeve including an integral position member , referred to hereafter simply as sleeve 12 , constructed in accordance with one aspect of the invention . the sleeve 12 is used , as least in part , to protect an electrical member 14 contained at least in part therein , such as sensor , against the effects of extreme radiant heat , abrasion , contamination and vibration . the sensor 14 is shown connected to an end of a wire harness 16 on an engine component 18 of a vehicle . the wire harness 16 can be provided as a bundle of exposed , insulated wires , or as a bundle of insulated wires enclosed within an outer protective sleeve , also referred to as tube 20 ( fig1 a ), 20 ′ ( fig1 b ), wherein the tube 20 , 20 ′ can have a corrugated or convolute outer surface 22 ( fig1 a ), or generally smooth outer surface 22 ′ ( fig1 b ), by way of example and without limitation . the sleeve 12 is configured for slidable movement along a longitudinal axis 24 of the wire harness 16 and tube 20 , 20 ′, if provided , to bring the sleeve 12 into its desired protective position about the sensor 14 . the sleeve 12 is further configured , via an integral positioning member made as one - piece of material with the sleeve 12 , as discussed in further detail below , to remain fixed in the protective position until desired to selectively slide the sleeve 12 away from its protective position , such as may be desired to service the sensor 14 . the sleeve 12 remains in its protective position during use via frictional engagement of the positioning member with the wires 16 or tube 20 , 20 ′ thereof , without need of secondary fasteners , such as tape or adhesives , and thus , assembly 10 is made simple and cost effective . the sleeve 12 can be constructed having any desired length . the sleeve 12 , as shown in partially constructed embodiments of fig2 a - 2c and respective finished embodiments of fig5 a - 5c , has a nonwoven inner layer 26 and a reflective outer layer 28 . the inner layer 26 , in accordance with one aspect of the invention , is constructed of a heat - formable nonwoven material , and can be constructed having any desired wall thicknesses ( t ), depending on the nature and severity of heat exposure in the intended environment . the nonwoven material forming the inner layer 26 is formed including heat - settable fibers , such as heat - settable low melt fibers including either monofilaments and / or bi - component fibers . the low melt fibers can be mixed with standard thermoplastic fibers and / or fiberglass and / or natural fibers of hemp , jute , keflex , or the like . the low melt fibers at least partially melt at a temperature lower than the remaining fibers when heat treated in a heat - setting process , whereupon the low melt fibers take on a solidified , heat - set configuration , thereby biasing the inner layer 26 and outer layer 28 to take on and retain a heat - set shape . if bi - component fibers are provided as low melt fibers , they can be provided having a core of a standard thermoplastic material , such as polyethylene terephthalate ( pet ), for example , with an outer sheath of polypropylene , polyethylene , or low melt polyester , for example . the standard thermoplastic fibers can be provided as any thermoplastic fiber , such as nylon or pet , for example , and act in part to provide the desired density and thickness ( t ) to the inner layer 26 , as desired , thereby providing additional thermal protection and rigidity to the sleeve 12 , while also being relatively inexpensive compared to the heat - settable fibers . accordingly , the inner layer 26 is constructed having a suitable thickness ( t ) and density of mechanically intertwined , or otherwise bonded , non - woven standard thermoplastic fibers and low melt fibers to obtain the desired physical properties , depending on the application , while also being heat - settable into a desired shape . the outer layer 28 is provided to reflect extreme radiant heat typical of an engine compartment , including temperatures generated by an exhaust system . the outer layer 28 can be formed of any suitable metal material , including a foil layer of aluminum or other desired metals . the foil outer layer 28 is relatively thin , thereby allowing the sleeve 12 to remain flexible over meandering paths and corners . the outer layer 28 is disposed about an outer surface 27 of the inner layer 26 , and can be spiral wrapped or cigarette wrapped about the nonwoven inner layer 26 , as desired . any suitable , heat resistant adhesive can be used to facilitate bonding the outer layer 28 to the inner layer 26 , if desired . in accordance with one presently preferred method of constructing the sleeve 12 , the nonwoven inner layer 26 is formed as a circumferentially continuous tubular wall , such as by being spiral wrapped , wherein the opposite edges can be brought into flush abutting relation with one another , thereby forming a butt joint 25 ( fig2 d ), to form smooth cylindrical outer and inner surfaces 27 , 29 extending between opposite open ends 30 , 32 . then , the foil outer layer 28 can be wrapped about , in spiral or cigarette fashion , wherein the foil layer 28 can have opposite edges 33 , 35 brought into overlapping relation with one another , and can be mechanically fixed or bonded to the outer surface 27 of the inner layer 26 . then , integral fingers 34 , also referred to as positioning members , end projections or locating and retention features , can be formed . in one embodiment , the fingers 34 can be formed in a cutting operation , whereupon some of the inner layer 26 and outer layer 28 is cut via any suitable cutting process to form slits or spaces 36 between adjacent fingers 34 . the spaces 36 , by way of example and without limitation , are shown as being generally v - shaped in fig2 a , though any desired shaped can be formed , thereby facilitating a subsequent folding operation , wherein the fingers 34 are folded radially inwardly to point generally toward one another and subsequently heat - set ( fig3 , 5a ). for example , as shown in another embodiment , rather than having v - shaped notches formed between adjacent fingers 34 , the slits 36 can be formed as straight or substantially straight slits ( fig2 b ), thereby forming generally rectangular fingers 34 , whereupon the fingers 34 can then be folded radially inwardly and subsequently heat - set ( fig5 b ). in this embodiment , it can be seen that the individual fingers 34 overlap one another along their radially extending edges , which can further act to provide enhanced protection to the sensor 14 . further yet , rather than forming slits or otherwise cutting the sleeve wall to form individual fingers , a desired uncut length ( l ; fig2 c ) of an end region of the sleeve wall can be folded radially inwardly without first cutting or slitting , whereupon a single , circumferentially extending finger 34 can be formed , having accordion - like , folded overlapping regions as a result of not having slits ( fig5 c ). the folding operation can be performed by first disposing the tubular wall on a mandrel , and then folding the plurality of fingers 34 or single finger 34 , depending on the construction desired , over an end of the mandrel to bring the inner layer 26 into abutment with a generally flat end of the mandrel . then , with the finger ( s ) 34 in the folded position , sufficient heat can be applied to the inner layer 26 to cause the inner layer , at least within the region including the finger ( s ) 34 , to take on a heat - set . the heat can be applied via a heatable mandrel and / or via an external source of heat . accordingly , the finger ( s ) 34 are heat - shaped to remain or substantially remain in the “ as folded ” position , thereby providing the sleeve 12 with a remaining cylindrical portion extending from one end 30 to the location , a newly formed end 32 ′ of the cylindrical portion of the sleeve 12 , where the finger ( s ) 34 are bent radially inwardly . in accordance with another aspect of the invention , as shown in fig5 a - 5c , it is contemplated that a resinous material rm could be applied to the inner layer 26 , at least on the region of the inner layer 26 forming the fingers 34 , or to the entirety of the inner layer 26 , if desired , to facilitate providing the material of the fingers 34 with the desired stiffness , rigidity , resiliency and flexibility desired to optimally function as retention and retaining members . further yet , as shown in fig6 and 7 , a separate support member in the form of a reinforcing layer of material , such as a plastic material , by way of example and without limitation , of desired thickness , resiliency and flexibility , such as a generally circular disc 38 , having through opening 40 sized and shaped similarly to an opening 42 formed by free ends 44 of the fingers 34 , could be bonded inside the sleeve 12 in abutment with the inner layer 26 of the fingers 34 . if provided , it is contemplated that the circular disc 38 would have slits 46 formed therein , as shown , with the slits 46 being arranged to register in axially and radially aligned relation with the slits or spaces 36 to allow the fingers 34 to remain resiliently flexible axially inwardly and axially outwardly along the axis 24 during assembly and removal of the sleeve 12 along the wire harness 16 . of course , it should be recognized the slits 46 can be formed to take on the same shape as the slits 36 formed between the fingers 34 , as desired . upon completing the heat - setting operation , the sleeve 12 can be removed from the mandrel , wherein the one - piece sleeve 12 is provided , without having to fasten other components thereto in secondary operations , having a cylindrical portion extending from the open end 30 to an end location 32 ′ where the fingers 34 are folded radially inwardly , without need of secondary fasteners to join the fingers 34 to the sleeve 12 . in use , the sleeve 12 can be easily slid over the wire harness 16 or tube 20 thereof , whereupon ends 44 of the fingers 34 engage and flex axially against the wires harness 16 or tube 20 . a predetermined amount of friction and interference between the finger end ( s ) 44 and the wire harness 16 or tube 20 can be provided by sizing the opening 42 bounded by the finger end ( s ) 44 in construction . as shown generally in fig3 a , with the fingers 34 being flexible and resilient , the fingers 34 are readily biased slightly axially via friction or interference with the wire harness 16 or tube 20 to flex axially away from the sleeve end 30 during installation and axially toward the sleeve end 30 during removal , such as may be required in service . if a tube 20 is provided as a corrugate tube ( fig1 a ), the fingers 34 can be biased to flex axially over annular crests c during installation and removal , and can be constructed to take on a predetermined thickness to be received within annular valleys v of the corrugations to facilitate maintaining the sleeve 12 in its intended “ in use ” position about the sensor 14 . in fig5 c , a sleeve 112 constructed in accordance with another aspect of the invention is shown , wherein the same reference numerals , offset by a factor of 100 , are used to identify like features . the sleeve 112 has an inner layer 126 and an outer layer 128 constructed of the same materials discussed above for the sleeve 12 . in contrast to the sleeve 12 , a single finger 134 is folded radially inwardly , however , the free end 144 of the finger 134 , rather than forming an opening for receipt of the wires 16 or tube 20 as folded , can be formed via a subsequent cutting operation , such as die cutting via a circular punch , or any desired outer peripherally shaped punch . as such , the through opening 142 can be formed having a precisely sized and shaped configuration , whether circular or other configuration , thereby resulting in a precision amount of interference between a free end 144 of the finger 134 . as such , it should be recognized that a single , circumferentially continuous finger 134 can be folded radially inwardly , and then the opening 142 can be cut . of course , this same mechanism for form the central opening can be used if a plurality of fingers 134 are formed and folded radially inwardly . if a single finger 134 is formed , the finger 134 has a plurality of overlapping folded regions 50 formed by the material of the finger 134 . further yet , it is contemplated that upon folding the single finger 134 or plurality of fingers 134 radially inwardly , the finished shape of individual fingers 134 can be subsequently formed in a cutting operation , in addition to the cutting operation used in forming the opening 142 . obviously , in light of the above teachings , many modifications and variations of the present invention are possible . it is , therefore , to be understood that within the scope of the appended claims , the invention may be practiced otherwise than as specifically described .