The device is designed so that {HEAD ~ the snapping sound} caused by the plunger hitting a wall synchronizes with {TAIL ~ the impact} on the muscles felt by the user during a hand motion 
synchronizes with
The device is designed so that { HEAD ~ the snapping sound } caused by the plunger hitting a wall synchronizes with { TAIL ~ the impact } on the muscles felt by the user during a hand motion
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH