3" PelletVent Pro Black Increaser Adaptor Tee with Clean-Out Cap 3PVP-TADX4B1 This increaser adaptor tee with clean-out cap is used for a 90 ° offset. Attaches directly to appliance as an adaptor. Converts a 3" appliance to a 4" PelletVent Pro system. One piece unit incorporates removable twist-lock clean-out tee cap. Use with pellet oil corn and bio-fuel appliances Laser-welded super ferritic stainless steel inner walls and galvalume outer walls Outer diameter is 5/8" larger than inner diameter 1" clearance to combustibles No additional gaskets or sealants needed The precise fit of twist-lock connections is fast secure and leak resistant. Adaptability is provided by swivel elbow connections and multiple termination options Laser-welded double-wall pipe with a .012†inner wall of corrosion resistant stainless steel and a .018†laser-welded galvalume outer wall. Painted black exterior available. Primary metal-to-metal connection seals joint. Encapsulated O-ring provides a secondary seal.