Along the body 8 is {HEAD ~ a plurality} of lateral, crescent shaped grooves 10, 12, disposed on opposite sides of {TAIL ~ the device} in alternating fashion 
Along the body 8 is { HEAD ~ a plurality } of lateral , crescent shaped grooves 10 , 12 , disposed on opposite sides of { TAIL ~ the device } in alternating fashion
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH