Material: stainless steel Leash attachment: O-ring attachment, easy on and put off. Recommend this for training your dog whether professionally or just a few simple commands like "sit", "lay down", "jump", "stay", "wait", and "NO". Never leave your dog unattended with this collar on. It is for training purposes only. Safe and effective way to train your dogs with our chain collar, designed to tighten under tension, correct the wrong behavior by pulling the leash with a gentle but effective feedback Size Guide: For choke collars, measure the circumference of pet's neck and add 2"–3" Safe effective dog training tools with proper use, these training collar provide a heavy-duty safe alternative to standard choke chains For dog relate product please search brand‘SGODA'