Selby's Precision Quality Thin Swivel is super strong and precision crafted with a rated capacity of 400 lbs.and 360¡ turning on captive ball bearings. It is extra thin, only 1/2"! Its non sag construction is .078 heavy cold rolled steel terne-plated for anti-rust protection. The plate is 6-1/8" square with a 3/8" center hole. This swivel is not for use on chairs or bar stools.