Easily slides over your dog's neck as a bright LED addition to an existing collarUniversal sizing: cut to fit from 12" - 27" | 30.5cm -68.5cmChoose from Disc-O mode or three selectable colors (red, green, blue)Disc-O mode features unique color-blending pattern360° of illuminationWeather resistantMicro USB rechargeable (cable not included)Battery run time: 5.5 hoursRecharges in approximately 1.5 hours