Adjustable from 4 1/2 to 6 1/2 inches 3/8 inches (10mm) wide Lightest and smallest puppy collar Lightweight side release buckle For ID purposes only! Listing is for one collar, due to the nature of this fabric every collar turns out different. This collar is one of my smallest, made with the lightest interfacing, making it finer and lighter for the tiniest puppies and the sensitive skin of tiny dogs. All my collars are made with light weight plastic buckles. While I love the look of metal buckles, I feel that they are too heavy for tiny puppies and dogs. This collar is adjustable from 4 1/2 to 6 1/2 inches in length and are 3/8th inches wide (10 mm).