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