The RDR Cobra buckle K9 collar provides the highest level of strength, function, and durability. This collar is built with AustriAlpine’s 1” cobra buckle, and is built out of 2 layers of 1.5” webbing, and 1 layer of 1” accent webbing. In addition, the collar comes with two dedicated D-rings, one robust D-ring for leash attachment’s, and 1 smaller D-ring for I.D. Tags. The combination of strength and functionality of this collar ensures it will meet the needs of every dog and handler. From civilian, to military and Law enforcement to service dogs. To properly size your dog, using a soft tape measure take his/her measurement to the tightest point desired. That number plus 2” is your dog’s final measurement Medium – 17”-21” Large – 21”-24” Ex Large – 24”-27”