This is the most effective, safe, and humane collar we've found that gives you added control over your dog. Safer to use than a choke chain, Martingale dog collars are favored by professional dog-show handlers because they offer much more control than standard buckle collars. Worn loosely, they tighten up only to a certain point to get the dog's attention and then stop - never choking. Nylon webbing. Steel D-ring. Unlike other collars, the measurement taken for the Martingale collar is at the top of the neck, directly behind the ears, to correspond with the size of the collar in the closed position. These dog collars feature quality nylon webbing. USA. Personalization not available when ordering through Amazon.