The M18™ ProPEX® expansion heads are precision engineered for accurate expansion of Uponor® PEX-a tubing for ProPEX® fittings. Featuring the auto-rotation interface for Milwaukee cordless ProPEX® expansion tools, the heads are not only compatible with M18™ tools, but also fit most Uponor® cordless tools. Made from high strength steel, the chrome plated segments and black oxide ring combine durability and weather resistance. Color coded rings for easy size recognition add convenience.