The Martingale Collar is a safer and comfortable alternative to a choke collar. The self-adjusting chain loop does not overcorrect or cause choking. When the dog pulls away, the martingale will automatically engage, producing an even distribution of pressure from the collar. The click of the chain provides an audible training cue that your dog will react to, which allows you to safely and effectively train your dog. The quick snap buckle enables easy on/off. Made of high quality, durable nylon for a lightweight, comfortable design suitable for everyday wear.