"Red-Blue-Orange" LED Flashing Blinky Lights (Light-up, Illuminated) Nighttime Safety Collar for Dogs - Parade Blue Size Medium collar measures approx. 1 inch wide and adjusts for neck girth of 13 inch to 17 inch Series of 6 L.E.D. Lights Flash "Red-Blue-Orange" in a repeated sequence - a brilliant way to keep your dog safely visible in the dark Constructed with durable 620 Denier nylon, hidden power pack with handy on/off switch and an adjustable stainless belt buckle and D-loop for ID tag and leash Best quality LED dog collar on the market! Weatherproof,?Shock Resistant?and Light Weight Powered by long-lasting easily replaceable CR2032 lithium batteries (pre-installed)