Coastal Pet Products DCP553018 18-Inch Titan Heavy Chain Dog Training Choke/Collar with 3mm Link, Chrome Titan dog training choke/collar is excellent for gentle control This heavy quality chain is argon welded and chrome plated for maximum strength and durability It will not tarnish, rust, or break and recommended for professional training Use only when dog is attended on leash and is sized by total length, including the rings Measures 18-inch overall length and 3.0-mm link diameter Note: While placing order make sure you purchase size that is 2-3 inches Larger than the exact size of your dogs neck.