These attachment pieces make it easy to swap your dog tag onto different collars. If you have a collection and hate trying to make sure you change over your pet's dog tag as well, this is for you! They are 38mm in length and come in silver. These do make the tag hang lower on your pet's chest, so they are not recommended for smaller dogs. Email us if you have questions regarding sizing for your pet or colors available! Note: Dog tags sold separately.