Z Vent III 3" Stainless Steel Vent Pipe 3" Diameter Starter Piece

3" diameter. Clamps and seals on both ends to clamp to heater and first piece of vent pipe. You will need this piece if you are purchasing Z-Vent pipe for your Hot Dawg heater. Z-Vent is a factory built, engineered AL29-4C special gas vent pipe, suitable for positive or negative pressure. Z-Vent is UL tested and listed to UL1738/S636. CAT II, III, IV venting approved.