These choke chains are guaranteed not to rust or break because they're made from top quality rustproof chain. Smooth chrome plating allow instant release. The links are electronically welded for strength. Note: The size of these colars includes from end of ring to end of ring. To order the correct size, measure around your dog's neck and add 2 1/2" to 3". Example: If your dogs neck measures 17 1/2", you will need a size 20.