This is a half-choke collar for small dogs, 2.5cm wide. The size is for dogs with a head circumference of about 28.5cm (at the hole position in the photo) and can be put on and taken off over the head. Some adjustment is possible, but please measure your dog carefully before ordering. 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: 2.5cm Thickness: Approximately 3mm (may vary slightly depending on the leather) Head circumference: Approximately 28.5cm Please compare this with the half-choke collar you already have. ● Leather part size: Approximately 24cm (at the hole position in the photo) ● Chain size: Approximately 9cm (The reason the total doesn't equal the ordered head circumference is because the chain and leather overlap, and it's calculated for a size that can be put on and taken off over the head.) Please contact us if you have any questions. +++++++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, including half-choke collars and leads, mainly for bulky collars for bully breeds and long-necked collars for 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.