Rapture Novelties Round Stainless Steel Collar. Stainless steel slave collar that locks with a stainless steel Allen screw. It is made of stainless steel rod that is a half inch in diameter. It has a high polish finish, and can be worn as jewelry. It is hinged on one side and secured with a flush mount locking screw. Additional Information: Solid Stainless Steel with polished Finish, Attached lead ring, Flush mount screw lock, The neck circumference is 15.5 inches or diameter of 4.75 inches. The collar thickness is 0.5 inch. Weight 14 ounces.