As shown in FIG 7a and further in FIG 8a, this action stretches {HEAD ~ the center section} of {TAIL ~ the fabric} between elements 48, 48, increasing the open space, i.e. porosity, of the fabric 
of
As shown in FIG 7a and further in FIG 8a , this action stretches { HEAD ~ the center section } of { TAIL ~ the fabric } between elements 48 , 48 , increasing the open space , i.e. porosity , of the fabric
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH