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