Safety Dog LED Collar Flashing Light up, Glow and Bright (Ships from USA) ''Be safe, be SEEN also applies to our four-legged friends! Glow Doggie Glow! Entire length of collar glows with bright LED light. 3 different LED light Glow settings to choose from- Blinking, strobe, or normal glow. Fully adjustable Led collar. Available in Small (S) Medium (M) Large (L) Small: 1" wide, fits necks 14-17 Medium: 1" wide, fits necks 15.5-19.5" Large: 1" wide, fits necks 17.5-23"