Sophia Self-Closing Door Hinge 3.5 Inch Rounded 5/8 Radius, Polished Brass The hinges feature a 5/8 inch radius self-closing mechanism and are made of durable steel construction. Designed for mounting on standard 1-3/8 inch thick doors. Don't let the door hit you on the way out! Plus, our self-closing hinges ensure smooth door closing while preventing a slamming sound. The self-closing hinges are adjustable spring tension which can you set to leave the door closed or ajar. It's huge for people who often forget to close the door. Pack includes two (2) self-closing door hinges and mounting all hardwares. If there is a quality problem during use, we will solve it for you to ensure your satisfaction and product reliability.