SMALLER INNER SIZE medium socket Rings -1-3/8 inches inside diameter,2-1/8 inches outside diameter | BAKELITE MATERIAL: rust resistant, insulative and relatively high temperature resistance ensures your safe use | WIDE APPLICATION -Use with medium base threaded sockets to secure different lamp shades,floor lamps,replace broke shade ring, hold light fixtures like hanging lights,pendant lights ect | EASY INSTALLATION, screw on and hold the shade at the same time,then job down. Replace or create a new lamp shade easily without additional tools | REMINDER-CHECK DIAMETER OF EXISTING THREADED SOCKET before buying.The screw rings ONLY WORK ON threaded socket 1-3/8 inches(34MM).If you have bigger threaded socket 1-1/2 inches(39MM),select our white aluminum shade rings ASIN#B08DTZ6HM9