This is a half-choke collar for large dogs, 4cm wide. The size is for dogs with a head circumference of about 50cm, and it can be put on and taken off over the head. It can be adjusted, but please basically use this size. This is a one-of-a-kind finished product (sample) and is a bargain. If you want a different size, please order from Yahoo! Shopping. Leather width: 4cm Thickness: Approximately 4mm (may vary slightly depending on the leather) Head circumference: 50cm (at the hole in the photo; can be adjusted to a larger size) ● Size of the leather part: Approximately 38cm (at the hole in the photo) ● Chain size: Approximately 15.5cm (The reason the total doesn't match the ordered head circumference is because the chain and leather overlap, and it's calculated to be a size that can be put on and taken off over the head.) Please contact us if you don't understand. ++++++About Extra+Heavy+++++++ We have many other items for sale, so please take a look. Extra+Heavy is a handmade collar shop that specializes in custom-made collars, half-choke collars, and leads, mainly for bulky collars for bull breeds and collars for long-necked dogs like Italian Greyhounds. Our sites are Rakuten Shop, Yahoo! Shop, and our main store. * You can find Extra Heavy by searching for "collar studs" on Rakuten Shop and Yahoo! Shopping Mall.