Black CTS Twist and Lock fittings from John Guest include 1/2-inch union tees, elbows and couplers (3/4- and 1-inch sizes available). Designed for water softener and domestic plumbing installations, the fittings are suitable for hot- and cold-water plumbing and hydronic heating applications. The fittings connect to any combination of CPVC, PEX or CTS piping. No tools or glue are needed. Fittings are made from high-quality engineered plastic with EPDM O-rings. 973/808-5600; www.johnguest.com.