This collar is unbeatable with construction with super bright L.E.D.s. It has 3 different light modes for complete visibility. Keep you and your pet safe at night. You will be seen for up to 1000 feet away. Beautiful! Strong & soft, lightweight. Fully adjustable. Available with black webbing only with 4 different L.E.D. colors to choose from : white, red, blue and green. Comes with 2pcs CR-2032 Coin Cell Batteries which are replaceable. Be seen and shine on! Small- fits 12.5"-15.5"x1" Medium - fits 15.5"-19.5"x1" Large - fits 19.5" - 24" x 1"