In the embodiment shown in FIGS 8A and 8B {HEAD ~ a button} 25 comparable to {TAIL ~ element} 24 is fixedly connected to a flexible closed end sheath 4 
comparable to
In the embodiment shown in FIGS 8A and 8B { HEAD ~ a button } 25 comparable to { TAIL ~ element } 24 is fixedly connected to a flexible closed end sheath 4
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH