LED Lit Camo Dog Collar- Size Large and Choice of 5 Colors - BONUS Extra Set of Batteries- Keep Pets Safe With 3 Safety Light Modes That Glow and Flash Bright These Pet Collars run on 2 replaceable CR2032 Batteries (included) and as a BONUS it also includes a second set of batteries for future use. BeSeen (TM) Dog collars are also shipped with an battery insulator strip for ease of first use and to ensure the batteries stay fresh during shipping. Simply pull the insulator strip away from the pre-installed batteries and your dog's collar is ready to be lit. Large camouflauge collars fit dogs with a neck size of 19" to 21"and is easily adjustable. Please measure your dog's neck prior to purchase to ensure a great fit, then add 2" so that it is not tight to fit. This will enable you to get 2-3 finger between your pet and the collar as recommended. The width of the collar itself is 1"wide. Pets can be made safer with this simple purchase. BeSeen Dog Collars shine bright so that you and others can easily see your dog. Feel safer that drivers will see your pet sooner while wearing an activated LED Dog Collar in low light situations. Also ideal for being noticed while walking your dog at dusk and dawn. Collar can be worn in the very stylish OFF position and also has 3 modes for the LED Lights- Constant on, Slow Blink, And Fast Blinking. You have your choice of mode for your pet and their safety. Can be worn everyday or can easily be snapped on when going out after dusk and during the dawn. All colors of this collar have a strong secure buckle and the collar itself measures 1" wide.