- Thick and Soft PU Leather Advantage - As you know, it’s hard to hold a bad macho dog. When you walk or train, the leather is always torn. Soft and thick PU leather gives you peace of mind 2. Dog Neck Defender by Sharp Rivets - The most troublesome situation is when your pet gets out of your control and attacks someone else. These spikes will get him up before you can do anything. 3. CHORMED D-ring for leash attachment - Sturdy D-ring, inlaid with plated mushroom comment for leash attachment, strong enough to walk or train dogs 4. Note: Rivets are very sharp and not safe for dogs and children. Please keep your dog under control while changing the collar