This chain training collar is constructed from a fine 2 mm gauge chain that is argon welded and chrome plated for added strength. The welded links are designed to resist tarnishing, rusting and breaking with everyday handling. It functions as a slip-style collar, tightening and loosening as tension is applied and released during leash correction work. The collar is sized by its total overall length, measured including the rings at each end, and is offered in several lengths to fit different dogs. It is intended for use as a training tool while the dog is attended on leash and is not designed or recommended for tie-out or unattended use. No assembly is required before use.