Nite Ize NiteDog Rechargeable LED Collar Blue/Blue Medium. Two ultra-bright LEDs send light through an integrated optical fiber to create full-length illumination so bright you need to see it to believe it. Featuring the convenience of rechargeability and easy push-button operation this collar lights up for more than six hours on a single charge. Nite Ize optical fiber technology transmits light throughout the entire length of the collar without loss of light output and offers both constant glow and flash mode. The high-quality metal belt-buckle style closure is simple to adjust. This highly water-resistant collar is designed for ultimate durability and is available in a variety of sizes to fit large and small dogs. Specifications for Nite Ize NiteDog Rechargeable LED Collar: Manufacturer: Nite Ize Included Accessories: Batteries Length: 24 in 20 in 16 in 12 in 17 in Depth/Thickness: 1.34 in Features of Nite Ize NiteDog Rechargeable LED Collar 360 visibility Integrated optical fiber and two high-powered LEDs provide full-length illumination Glow or flash Easy push-button operation Water-resistant High-quality metal belt-buckle style closure for quick and easy adjustmen Strong metal D-ring Recharges in approximately 1.25 hours using micro USB cable (not included) Run time: 6.5 hours Small: 12"- 16" 30.5cm - 40.6cm Package Contents: Nite Ize NiteDog Rechargeable LED Collar Nite Ize NDCRM-03-R3: NiteDog Rechargeable LED Collar Blue/Blue Medium