Nite Ize LED Nylon Night Safety Dog Collar Red - Small Patented L.E.D. illumination is visible up to 1000 feet in the dark Nylon collar is strong, flexible, and weather resistant; LED switch can be removed for water play L.E.D. has two modes: flashing and steady glow; long life replaceable battery included 3 adjustable sizes: small 10 to 13 inches, medium 13 to 18 inches, and large 18 to 27 inches LED polymer tube inside nylon collar can be shortened for a custom fit