Product Type Venting For Gas Heaters Compatible with Product Type Wall Furnaces Compatible Grainger Part Number 4LFZ5 4LFZ6 4LGA4 4LGA5 Compatible Mfr Model Number DV-20E DV-40E Opening Height 2 in Opening Width 3 1/4 in Opening Depth 2 in Mounting Type Surface Vent Direction Vertical Vent Length 54 in Vent Diameter 2 in Vent Size 2 in Vent Type Intake/Exhaust Extension Kit Material Rubber Silicone Stainless Outer Diameter 2 in Pattern Angle 90 Degrees