Large size, commercial grade, Retro-Split Rubber Storm Collars weatherproof process piping and irregular structural steel support column profiles that fit within a 12 in. Dia circle including large size pipes, structural supports and conduits. Precise geometric shapes are pre-molded into the top plug of a Retro-Split Storm collar which opens to permit mounting onto a penetration from the side. Each collar includes a wraparound skirt with tabs that fit into pre-molded slots fashioned inside the top plug. The Retro-Split wrap around skirt forms a conical shape and is held tight by a patented Press Together latch. 1 Top Plug, 2 Skirt Sections and 1 Stainless Steel band clamp combine to make a weatherproof storm collar umbrella counterflashing placed directly above a roof flashing. Retro-Split Collars are made from Ethylene Propylene Diene Monomer (EPDM) rubber that is exceptionally resistant to heat, ozone and acid rain assuring long-life that should exceed 20-years. An EPDM rubber collar will always spring back from pedestrian impacts, cannot corrode, never affects metallurgies, resists UV light, and can disassemble for roof maintenance or reuse. A Roof Flashing is not included as part of the Retro-Split Storm Collar assembly. Unequivocally, the easiest to install, and best looking retro-fit storm-collar flashing. Do-It-Yourselfers and Pros who have pride in their work, always use the best; A Retro-Split Storm Collar.