Vegetable-tanned leather, handmade Width: Approximately 10mm Thickness: 4.0mm Length: 54cm (excluding hardware) Head opening: 49cm A document on how to use a choke lead and choke collar will be included for those who purchase this item. Also included will be training methods I used for two flat-coated retrievers, including how they learned to walk off-leash (though they usually wear choke leads, etc.) and stay within 50cm of me, as well as training methods for a dog that bit my husband's lip four times. Dogs that can maintain eye contact (releasing the happiness hormone, oxytocin, which enhances communication skills in both parties) are easier to train. Dogs that could walk off-leash looked at me every 15 seconds. Training methods to achieve this will also be included. Dogs can be trained at any age. Research shows that dogs are unique among animals in maintaining the brain flexibility of a puppy even as adults. This is a factor in their evolution from wolves. Recommended width: Up to 15kg: Approximately 10mm or approximately 12.5mm 15-28kg: Approximately 12.5mm or approximately 15mm 28-35kg: Approximately 15mm or approximately 17.5mm 35kg and up: Approximately 17.5mm or approximately 20mm 15mm is generally optimal for retrievers Leather leads are safe because they are less likely to slip when pulled and do not burn due to friction. Therefore, they are also safe for dogs. *Ideal for training. When you learn to use a choke collar correctly, you can not only control your dog but also build a relationship of trust. You will also be able to control large dogs with your wrist. (Instructions on how to use the lead to prevent pulling while walking will be included for your dog's health.) *The basic rule is for the dog to walk on the left side of the person holding the lead. Use the choke collar and lead to give the dog a cue to come to the correct position next to your left knee, and then loosen the lead when the dog is in the correct position, allowing the dog to figure out what to do. (As a precaution during walks, when passing cars, people, or other dogs in the city, the person holding the lead should position themselves between their dog and the other party.) If you comment with your desired type, width, and length, I will do my best to accommodate your request. #DogCollar #VegetableTannedLeatherCollar #TrainingCollar #Collar