Nite Ize SpotLit Disc-O Select Collar Light - The SpotLit is a bright little LED collar light designed to keep your dog visible at nite. With Disc-O Select, you can choose one of six colors to easily identify multiple pets or leave it in color-changing Disc-O mode. Features: Weather resistant Secure stainless steel carabiner clip easily attaches to pet collars, harnesses, and leashes Push button on/off Choose from 6 selectable colors (red, purple, blue, aqua, green, white) or Disc-O color changing mode Two easily replaceable CR2016 3V lithium batteries included Battery run time: 20 hours