Medium size, commercial grade, Retro-Split Rubber Storm Collars weatherproof process piping and irregular structural steel support column profiles that fit within a 6 in. Dia circle including up to Nominal Pipe Size (NPS) 5.0 in. (5.563 O.D.) conduit. NPS being the standard for North American round pipe. Precise geometric shapes are pre-molded into the top plug of 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, 1 Skirt 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 to assure long-life that should exceed 20-years. An EPDM rubber collar will always spring back from pedestrian impacts, not corrode, affect metallurgies, resists U.V. light and disassemble for roof Maintained 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.