Mason-Lite B-Vent 12" Storm Collar sqft1240 The heating area varies according

The heating area varies according to the heater's length

12″ instead of 16″ for See Thru) for reduced framing requirements

Surly sturdy enough material leaves you no worry about using reliability

Optional concrete top pieces

unreasonable used

Mason-Lite B-Vent 12" Storm Collar sqft1240 The heating area varies accordingB Vent is a GAS ONLY metal chimney with smaller diameters. For those fireplaces requiring complicated chimney runs, B Vent may be just the answer. What's Included Storm Collar Features Used above the Flashing to provide weather strip seal to pipe. Seal the inner edge with sealant against pipe Specifications Item Number Mason Lite 12BVSC Product Type Storm Collar Venting Type B Vent Size (Diameter) 12" Dimensions Size 10" (I. D.) A 11" (O. D.) B 16 1