The Easy Leash is a great new leash designed with bungee inside to provide enough resistance that your dog cannot keep pulling on the leash when you go for a walk. When the dog tries to pull on the leash, they can stretch it some, but the constant resistance does not allow them to continue to pull. This is what trains your dog to stop the bad habit of pulling. There are 4 different sizes to ensure the dog has the correct amount of resistance. The extra small is for dogs up to 10 lbs, the small is for dogs 10-30 lbs, the medium is for dogs 30-70 lbs, and the large is for dogs over 70 lbs. We offer different lengths in this leash to help in the training of your dog. The 4 foot length is the best for dogs that pull a lot, are out of control, or that you would like to train faster (you can train a dog much faster with a short leash than a long one). The 6 foot length leash is fine for dogs that have the occassional pulling problem. We also offer an "extender" that you can attach to your own leash. Our 4 and 6 foot length leashes have a wonderful padded handle on them for your comfort.