beyond the top edge of aperture 50 whereupon stressed fingers 94 will snap outwardly to assume the position as shown in fig1 in this position radial shoulders 102 will engage lower support component 13 which surrounds aperture 50 firmly mounting attachment device 16 on support components 13 once piston attachment device 16 is inserted through aperture 50 mounting stud 28 of piston 22 is inserted through opening 110 defined by the free ends 101 of tangs 104 as mounting stud 28 travels through opening 110 camming surface 122 of stud 28 contacts the upper surface of tangs 104 which act as a camming surfaces to flex tangs 104 outwardly until shoulder 124 passes beyond free ends 108 of tangs 104 whereupon the stressed tangs will snap inwardly to assume the position shown in fig1 in this position radial shoulders 124 will engage the bottom free ends 108 of tangs 104 it is noted that the free ends of tangs 104 lie in the horizontal plane and thus abut flushly against shoulder 124 to assure a uniform holding power the vertical lengths of tangs 104 are equal to the distance from shoulder 124 to annular recess surface 29 such that free ends 108 of tangs 104 abuts above shoulder 124 and the attached ends abuts annular surface.