Safety Dog LED Collar Flashing Light up, Glow and bright (Ships From USA) (Small, Pink) Available in 5 Sizes, XS , S , M , L and XL . All of the collars are 1 inch wide except the XS which is 0.5 inch wide. 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" 3 different LED light Glow settings to choose from- Blinking, strobe, or normal glow. ''Be safe, be SEEN also applies to our four-legged friends! Glow Doggie Glow! the Led is strip is about 6 inch and the collar is adjustable