DuraVent 3PVP-06B 3" Inner Diameter - PelletVent Pro Type L Chimney Pipe - Doubl, Black Laser-welded, double-wall pipe with a .012" inner wall of 444 Stainless steel Outer wall of .018" laser welded Galvalume Encapsulated O-ring gives secondary seal to system. 1" clearance to combustibles in the US and Canada. Short length of pipe works well between offsets.