{TAIL ~ The block member} moves from a first position to a second position by {HEAD ~ contact} with the slider sliding in a sliding direction to block and open the air passage 
{ TAIL ~ The block member } moves from a first position to a second position by { HEAD ~ contact } with the slider sliding in a sliding direction to block and open the air passage
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH