The Light Niche/Return Fitting is designed to slip over a 1-1/2" pipe or inside a 2" pipe, enabling a 1-1/2" light socket to thread directly into the face. It features an integrated water stop to reduce leaks and enhances the appearance of the niche by eliminating the common unsightly silver. The 37xx-CS model includes a cap with a silicone O-ring to seal pipes during winterization. Made from UV-resistant engineered polymer ABS.