3600 Series Side Mounted Vacuum Relief Vent; Standard Construction; 4" Inlet Size, Mates With Standard ASME 150# Flanged Connection; Flat Face Derakane 470 Body & Cover, W/SST Studs, Derakane 470 Trim; Fep-Tfe Pallet Diaphragm; Special Encapsulated Weight Option For Frp Body Material Only