Please note the size - there are 3 sizes available. S: 30-43 cm, it is 1.5 cm wide. M: 35-48 cm, it is 2 cm wide. L: 40-53 cm, it is 2.5 cm wide. Suitable for small, medium and large dogs. Please measure your dog's neck circumference before ordering. Adjustable - buckle and stainless steel martingale chain can be adjusted, can help you adjust the appropriate length for the pet to make wearing the dog more comfortable. Dog collar material: made of durable PU leather, it is super strong and thick soft to irritate your dog's neck. Ensure safety and comfort for your pet. Metal fittings are made of stainless steel, sturdy and resilient. Secure attachment - Collar comes with a buckle and two D rings for attaching. The stainless steel O-ring provides secure attachment points for the lead and ensures that the lead is always attached to the right place. Martingale collar - Martingale collar allows you more control over your pet without the choking effect of a slip dog collar, stainless steel martingale chain that corrects the behaviour of the dogs, it tightens but does not choke, the martingale collar allows a safe and effective training with your dog. Very suitable for daily travel and training use.