3M™ Cold Shrink Silicone Rubber 3/C Cable Breakout Boot 8561 has a 0.48-0.72 in (12.2-18.3 mm) phase shield range and a 1.17-1.94 in (29.7-43.3 mm) outer jacket range. It is an open-ended molded rubber sealing assembly that has been factory expanded and mounted on a removable plastic core.3M Cold Shrink Silicone Rubber 3/C Cable Breakout Boots 8561 through 8566 are a series of open-ended molded silicone rubber sealing assemblies that are factory expanded and mounted on removable inner supporting plastic cores. They are supplied for field installation in a pre-stretched condition. The supporting cores are removed after the seal has been positioned for installation around the breakout area of a 3/C (three conductor) cable. Core removal allows the silicone rubber boot to shrink down to a predetermined diameter, creating an environmental enclosure for individual cable phase legs and overall cable jacket.