This waterproof safety and locator light comes in a choice of five colors, all of which will either shine constantly or flashing, selectable with the push of a button. Up to 250 hours of on-time light on two replaceable CR2032 batteries. Fits both 1” and 3/4” collars. Cute little spud comes with its own carabiner in case you want to hang it somewhere. Specify color when ordering.