Available in 16mm, 20mm, 25mm or the ‘sighthound’ widths of 38mm and 50mm. These collars are designed to be slipped over the head and adjusted to the neck size once on, so when choosing a size, please measure the largest part of your dogs head. These collars are lighter weight as they are primarily designed to hold the ID tag and have the least amount of bulk (commonly used for dogs that are walked on a harness), although the hardware we use is still strong!