This ICON Technology Hub is designed for transitioning from polyethylene holding tanks to ABS plumbing. A 3" female slip end with O-ring is included. A butyl sealant and a hose pipe clamp can be used to seal the hub to a molded polyethylene collar. Includes 3"" female slip end with O-ring Butyl sealant & hose pipe clamp can be used to seal hub to polyethylene collar | Icon Technologies RV Holding Tank Fitting, 3" Hub