3"D, Square, PelletVent Horizontal Cap, For Use With Horizontal Terminations Only, Cap Features Swivel Collar To Adjust Exhaust Direction, Cap Features An Optional Swivel Base, Designed For Stoves That Burn Wood Pellets, Patent Pending Venting For Stoves & Inserts That Use Wood Pellets, UL Listed For 3" Clearance To Combustibles In The USA & Canada.