Solid brass, Square socket Squat castors. Available in a range of sizes from 5/8" (16mm ) internal diameter of the socket, right up to 1.1/8" (28mm) size. The larger sizes are often used in the upholstery trade on the legs of sofas and settees, and on the front legs of antique drawing room chairs. Supplied with colour matched brass woodscrews. Traditional fitting made in Birmingham, England. n.b...Ordering size is internal dia. at top.