Designed for use in the water softener and domestic plumbing markets, the John Guest® ProLock Fitting Range is available in 0.375- to 1-inch CTS sizes. Manufactured from high-quality engineered plastic with EPDM O-rings, these fittings can be used with any combination of copper, PEX or CPVC pipe without the need for any tools. The push-to-connect fittings use Twist-to-Lock technology, which provides users with extra security when fittings are twisted into the locked position. Proven to reduce installation times by over 40 percent, ProLock products are also code-approved and approved for behind-the-wall use. Claim your free sample coupler by visiting the website.