in the embodiment illustrated in fig1 the packaging unit 1 of the invention comprises an applicator 3 and a first reservoir 5 for a product , in this case mascara . as compared to the prior art , this unit is extra flat . thus , the width of the packaging unit , measured along the straight line which is perpendicular to the plane of the handle , preferably ranges from 4 mm to 12 mm . the applicator 3 is provided with a flat handle 7 and an extra flat part 9 with bristles directly fixed to this handle and extending parallel to the plane of the handle . the part 9 with bristles is constituted by several tufts 12 of aligned bristles , the bristles 11 having lengths , shapes , diameters , cross - sections and other characteristics which may be preselected according to the loading , low or high , which is intended to be applied to the keratinous fibers . at least one portion of the bristled part 9 dips into the mascara . a portion of the handle 7 may dip into the first reservoir 5 . the bristled part 9 has an overall effective length to ensure an optimum loading of the keratinous fibers and in particular of the eyelashes . this length is substantially equal to that of the first reservoir 5 . in particular , this length ranges from 4 to 60 mm , preferably from 5 to 40 mm . the handle 7 is mounted on a cap 15 which functions as a lid and which releasably engages first reservoir 5 by cooperation of groove 7 and bead 4 . this first reservoir 5 has a neck 17 whose internal wall 29 is provided with a wiper 19 , one end 22 of which , situated opposite the cap 15 , is fixed on this neck 17 . in another embodiment of the invention , the end 22 can bear on the neck 17 of the first reservoir 5 . the handle 7 has a sealing system at the level of the end 22 of the wiper . this may be the gasket 21 or a washer bearing on a flange . the wiper 19 has on the opposite side to its fixed end 22 , a free end 24 wherein an opening 8 is arranged for the passing of the bristled part . this opening is of an oblong shape or has the shape of a flattened ellipse and its major dimension is perpendicular to the part with bristles , so as to smooth the bristles along their axis when the applicator is being withdrawn . the wiper is capable of wiping the bristled part along the axis of the bristles . it may comprise , at its end 24 , another sealing system that can be used on its own or together with the sealing system of the handle . the wiper may be made of a rigid or semi - rigid material , preferably chosen from elastomers or thermoplastic materials . in the embodiment of this fig1 the packaging unit is closed , and the opening 8 of the wiper is situated opposite the fixed end 26 of the bristled part . it is possible to position this opening 8 opposite the handle 7 . in this case , the wiper must be shaped according to the shape of the handle to ensure the wiping of the handle and of the bristled part 9 , always in the longitudinal direction of the bristles 11 , when the applicator is withdrawn . preferably , the fixed end 26 of the bristled part is situated in the vicinity of the opening 8 of the wiper . this packaging unit may have an overall length which is 3 to 6 times smaller than that of the conventional packaging units . advantageously , the overall length of the packaging unit in accordance with the invention ranges from 1 to 10 cm , and preferably from 1 to 5 cm . in practice , when the user withdraws the applicator 3 from the reservoir 5 , the wiping of the bristles 11 is effected at the level of the opening 8 of the end 24 of the wiper 19 . by being effected parallel to the longitudinal axis of the bristles , this wiping does not shear the formula of the mascara . such a packaging unit thus makes it possible to use compositions that are generally susceptible to the shear phenomenon , and makes it possible to use new mascara formulations . according to a preferred embodiment of the invention , the mascara may be contained in a flexible pouch 20 , shown in fig2 having an opening 25 . the opening 25 has a cross - section equal to the internal cross - section of the neck 17 of the reservoir , the edge of this opening 25 being positioned between ( i ) the internal wall 29 of the neck 17 and ( ii ) the end 22 of the wiper 19 . the end 24 of the wiper 19 is situated inside the flexible pouch 20 . the dot - dash lines show the position of the flexible pouch 20 at the start of withdrawal of the applicator . due to the low pressure , the walls 10 of the flexible pouch are then drawn in and adhere along the bristled part 9 which is thus loaded with mascara spread over the bristled part 9 by the internal walls 10 of the flexible pouch 20 . the packaging unit of fig3 is distinguished from that of fig1 by the flexible handle 7 and a secondary reservoir 35 for mascara , performing the function of a refill and a cap 31 . the handle 7 is here made of two parts articulated at a hinge 33 . such a flexible handle imparts greater softness and flexibility to the making - up . the first reservoir 5 containing the bristled part 9 , and the secondary reservoir 35 , are disposed symmetrically relative to the hinge 33 . by washing the unit and more particularly the bristled part 9 , two different mascaras can be used in the two reservoirs 5 and 35 . for instance it is possible to use a blue mascara and a black mascara . the secondary mascara reservoir 35 as well as the first mascara reservoir 5 may each contain from 0 . 5 to 10 cm 3 of the product , preferably from 1 to 5 cm 3 . this capacity may constitute half or a third of the conventional capacity of known mascara containers . this small size makes it possible to avoid drying of the product , which can be completely used up before drying out and can thus retain an ideal texture throughout its use . fig4 shows the secondary reservoir 35 in perspective . it is identical with the first reservoir 5 and may replace it when the first reservoir is empty . with a view to preventing the mascara from flowing out and ensuring the proper preservation of the mascara , a tearable cover 28 is provided . a stopper or catch engaged on the reservoir 35 may also be used instead of this cover . the packaging unit shown in fig5 is distinguished from that of fig1 by its closing system which is here a shackle 13 . the applicator and the first reservoir are kept together by means of this shackle , one of whose ends 14 is joined to the first reservoir . in another embodiment of the invention ( not shown ) the end 14 of the shackle 13 may be joined to the cap 15 . fig6 a and 6b show a variant of the packaging unit 1 of fig1 whose handle 7 comprises a part 16 articulated round a hinge 18 , allowing the applicator to be gripped at the side . in the open position , as shown in fig6 b , this part 16 thus forms an element for gripping the applicator at the side . fig6 a shows the applicator when the part 16 has been closed again . the packaging unit of fig7 has an articulated handle 8 with a hinge 37 . the notch 38 holds the handle in an inclined position . the packaging unit in accordance with the invention has the advantages that it is rechargeable and that it can be easily carried . thanks to such a packaging unit , waste of the product , due to the excessive capacity of the reservoir of the known devices , is prevented . such a packaging unit is very easy to make : it can be made of any material generally used for the manufacture of cosmetic accessories . since the applicator does not have a central metallic core , the packaging unit can be made solely from organic materials , and in particular solely of plastic materials , and can therefore be completely recyclable . obviously , numerous modifications and variations of the present invention are possible in light of the above teachings . it is therefore to be understood that the invention may be practiced otherwise than as specifically described herein .