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