Best In Show Chain Collection by H.D. & Co. Size: 2.5 mm Link x 18 inches long (see images for link size comparison). These Show Chains are a favorite of dog show enthusiasts needing a very light weight chain. Available in even size increments, this is an attractive, light-weight, slender chain ideal for show presentation and can be used for daily casual use with tags. View all images to decide which link size is appropriate for your use. The chain length is measured from ring to ring. For the initial collar fit, measure around the widest part of the dog’s head AND the dog's neck, then add 1 to 2 inches to the largest measurement. This will ensure that you can easily slip the collar over the dog's head. Choose chain length accordingly.