Keep a submissive in-line and in control with this Thick Stainless Steel Locking Collar. The durable and heavy steel will remain firmly around the neck. The collar opens and locks with a stainless steel screw; a screw driver is supplied. The collar has one O-rings for attachment to leashes, chains, ties or other bondage gear. The inside diameter is 5.5 in., the collar height is 1 in., the thickness is 0.2 in., the circumference is 17 in. Weight is 18 oz.