This model has the largest fin of the three models, and is recommended for areas that experience severe snow conditions. The VentSaver HD Series is made from non-corrosive, powder-coated aluminum and stainless steel aircraft cable. Stainless steel nuts, bolts and heavy duty 1 1/2" lag screws are provided for fastening to the roof.. The HD Series will fit up to 12/12 pitch and an infinite array of sizes from 1" to 14" around. Designed to fit vents, chimneys or stack pipes that measure 1" - 14" across and it protects a standing profile of approximately 14". Included is a snow diverter wing kit for panel valleys measuring 16" or wider. Please note that there is a minimum of 16" of flat area required between the major ribs, centered behind the pipe, to use the snow diverter wing kit. Wing kit spacers are provided to straddle minor ribs, if present in the panel. The use of the wing kit is optional and is not required.