Petmate's Mighty Link Chain collars are great as a training collar when used correctly. Guaranteed against rust, tarnish and breakage, Might Link collars are created with nickel and chrome plating for durability. Be sure to keep in mind the weight of the chain in comparison to the size of your dog as a heavy chain will cause smaller dogs to tire quickly. Choose the perfect length by adding 2-3" to the circumference of your dog's neck. To be sure the collar is on correctly, allow the collar to hang down. When looking at your dog, the collar should form a "P" shape. Available in a variety of lengths and thicknesses.