Back by popular demand the Fi Fastener 3 FLEX!!! This new generation of Fi Fastener Flex is made to support both version of the Fi 3 in circulation today and builds on new technology. The body of the Fi Fastener 3 FLEX is soft to make getting the Fi in an out much easier while still holding the unit totally secure! We coupled this with aircraft grade aluminum rivets to our dual J-Clip design made from space age Nylon Carbon Fiber the same material we use for our Quick Draw Bear Spray Holders. This Clip design allows you to add the Fi Fastener to any collar up to 1.25 inches wide and we offer a 1.5 and 2 inch version as well. With this blended, lower profile design the Fi Fastener Flex works great for dogs of all sizes an activity levels, including rough players, adventurers and couch potatoes! The Fi Fastener 3 comes in a whole new wide array of colors and is backed by our no questions asked Life Time replacement warranty!