【Adjustable Length】 ROJF nylon collar is easy to adjust, comes in only one size ranging from 8 inches to 22 inches for a comfortable, safe fit on suitable for puppies, small, medium, large dogs. Please make sure leave 2 fingers between neck and collar. 【Durable and Comfortable】This martingale collar is made of high density nylon, the webbing is super soft, which is more comfortable than other nylon straps and won't cut the dog's neck from friction. The dog chain is made of 316L stainless steel metal and will never rust or be tarnished for years of use. 【Training Dog Collar】This martingale-style limited cinch collar for dog is back out of traditional collars, it provides a more gentle, even correction with an audible cue that tightens evenly around the neck, but only tightens enough to provide a (subtle) controlled training cue to your dog, to make training with your dog safe and effective. The traditional choke collar is aggressive and uses uncontrolled force to correct negative behaviors. 【Increased safety】This collar is the ultimate balance between durability, functionality. Enhance your training with our chain-based martingale collar. The premium stainless steel components of our collar create an audible sound that further reinforces your training. The sturdy O-ring keeps your dog safely on the leash, so you can enjoy every walking and adventures. 【Escape-Proof Collar】ROJF no slip collar follows the traditional martingale collar design without buckle, can make your dog get the maximum comfort when wearing it, and reduce the chance of your dog slipping out of their collar in new situations or environments where your dog may get excited. making this limited slip dog collar a great training tool for controlled walks.