When {HEAD ~ an occupant} of {TAIL ~ specified or higher weight} sits on the seating surface, the protuberances collapse and the force translation plates activate the switch mechanism 
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When { HEAD ~ an occupant } of { TAIL ~ specified or higher weight } sits on the seating surface , the protuberances collapse and the force translation plates activate the switch mechanism
OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH