Hoffman 401475-1/8″ Straight Air Vent for Hot Water Steam Heating Convector
Hoffman 401475-1/8″ Straight Air Vent for Hot Water Steam Heating Convector Air Valve, # 508. Hoffman 508 radiator water vent valve, 1/8″NPT male straight shank, 50lb maximum. For automatic or manual venting of radiators, disc type vent with built in check valve.