Flair-It 3/8 PEXx3/8 PEX Elbow. This compression fitting is compatible with any brand or type of SDR-9 PEX or PE-RT tubing as well as Polybutylene pipe. Made from durable Polyoxymethylene material, it is resistant to stress fractures and extreme temperatures. Installation is easy - simply cut the tubing square, slide the nut along the tubing, rock the fitting all the way into the tubing, slide the nut back onto the fitting and tighten it as far as it will go. Flair-It fittings are lead-free and corrosion-resistant, making them a cost-effective alternative to brass. No crimp tool is required due to the patented design consisting of a nut and flared insert.