1. SIZE Please note: measure your dog's neck before placing an . Please refer to the size chart: M adjustable 37 46cm, L: adjustable 43 55cm, XL adjustable 47 66cm. Measure your dog's neck with a tape measure at the preferred resting point for the collar. Always allow sufficient breathing space to work. 2. material: density nylon fabric, wear resistant and tensile resistant. Backing material: soft, thickened diving material, breathable and shockproof. Training collar for dogs, soft to wear, more breathable and moisture absorbing, up to a larger circumference, relieves the tension caused by traction during actions and running. 3. Durable dog collars. The metal dog collar with quick release metal buckle and slider is easy to adjust and put on and take off. Quick release metal buckle with a smooth locking mechanism. Equipped with a large D ring for quick and easy leash attachment. 4. Practical design: for Mastiff, German Shepherd, Pit Bull, Labrador Retriever, Australian Shepherd, Boxer, Pointer, Puppy, American/English Bulldog, Siberian Alaskan Husky, Doberman, Rottweiler, Belgian Malinois, Hurley Dog etc. for small or medium to extra large dog breeds and ideal for dog training, patrol, hiking, hunting, camping, work. Running, jumping, travelling camping, etc.