The Lunalinx Glow Collar was created exclusively for safety, allowing you to see your feline friend, even in the dark. Long used in the traffic, aviation and rail industries, this material glows-in-the-dark without the need for batteries. Just expose it to daylight or intense indoor lighting and these collars will glow for hours. The Break Away Safety Buckle is designed to release if snagged and the collar is adjustable to fit most cats.