The Westinghouse Lighting Vertical Phenolic Snap-In Socket can be used to replace a worn or broken socket or to create a new handmade light fixture. Its vertical alignment means this socket is ideal for ceiling-mount light fixtures. The phenolic construction makes it durable and heat resistant, and the snap-in design makes the socket exceptionally easy to install. This socket uses one medium-base bulb and fits into a 3/8-inch by 1/4-inch hole. It is UL listed and CSA approved for safety.