SE Pet Safety Illuminated 21-30" Dog Collar Large Glow In the Dark Improve your best friends safety day or night by making him/her ultra-visible! Flashing LED-illumination technology with high-reflect material visible in low-light up to one mile Strong, durable &amp; comfortable 1 inch nylon-web belting, size-adjustable with secure quick-release buckle Lightweight and weather-resistant; large stainless steel D-loop for license/ID and leash 100,000 hour flashing LED have excellent battery-life; easy to replace CR2032 battery included