These collars have thicker leather that prevents the letters from sliding. Bling Bling! Yup, rhinestone jewels with matching collars can be worn around our lil friends and show off to the rest of the world! Collars are all 3/8" wide. Sizes: Small 8-9.5" L, Medium 10-12" L, and Large 13-14.5" L. Collars and letters are sold seperatly. These are for looks only and are not to be used with a leash.