This appears to be a leather product, as it was made by a leather craftsman. I don't know the details. I tried it on and it was too big, so I made three extra holes. My dog doesn't like wearing collars, so I haven't had a chance to use it. Length: Approximately 54.5cm, excluding the hardware Width: Approximately 2.5cm Length to the center of the first hole: Approximately 5cm Hole spacing: Approximately 2cm center to center 5 holes made by the craftsman 3 holes I made myself Thickness: Approximately 3mm (approximate measurement) Surface: There is one round stain. In addition, since it has been stored as is, you can see some light dirt when viewed from an angle. Please refrain from purchasing if you are concerned. The hardware seems sturdy. Shipping will be via Nekopos and delivered to your mailbox. #dog #collar