Zehui White LED Dog Night Safety Collar Flashing Light Up Blue Nylon Collar Size:M: 40-48cm Width: 2.5cm LED light glows and flashes in darkness. Helps to keep you and your dog & other pets safe during walking. Also work as a decoration: let your dog more attractive. Easy to use: simply pushing the control button makes the light ON/FLASH/OFF. 2 * CR2016 button batteries (pre-installed) Pet Bust Size:M: 40-48cm Width: 2.5cm