John Guest Push-to-Connect Water Softener Couplers are the easiest and most dependable way to join Copper, PEX, or CPVC pipe in any combination with no solder, glue, or tools required. JG fittings use a collet with stainless steel teeth that grips the pipe when fully inserted, and an EPDM O-Ring to provide a permanent, leak-proof seal. When twisted into place, the locking cap locks the pipe ensuring maximum security. Disconnection is just as easy with no tools needed; simply twist the cap counterclockwise to unlock then depress collet against the fitting to remove the pipe. JG Speedfit Twist-to-Lock fittings are suitable for hot and cold potable water and hydronic heating applications. Code approved for behind-the-wall installations.