Titan Chain Training Prong Collar is argon welded and chrome plated for maximum strength and durability. It will not tarnish, rust or break. Featuring a link closure style, prong links unfasten for easy collar placement and removal. Extra links and vinyl comfort tips are available. Available in 2.0 mm x 14", 3.0mm x 18", 3.3 mm x 20" and 4.0 mm x 22". Chain training prong collars are safe, effective training tools with proper use. They are not to be used for tie out.