{HEAD ~ An assembly} 15 wherein {TAIL ~ a pullout force} of at least 25 pounds is required to pull the heater out of the housing 
wherein
{ HEAD ~ An assembly } 15 wherein { TAIL ~ a pullout force } of at least 25 pounds is required to pull the heater out of the housing
HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH