Paws & Pals OxGord LED Pet Neck Collar Flashing Color Light Up Night Safety Strap, X-Large, Blue DIMENSIONS: For pets with a neck circumference of at least 17.75 inches. Maximum is 23 inches. KNOW WHERE YOUR PET IS AT ALL TIMES: Neck collar comes in four modes: Steady, Fast Flash, Normal Flash, and Off. Easily keep track of your pet at night. LIGHT UP THE NIGHT: Adjustable and durable design conforms to your pet. Collar uses two (2) CR2032 3V Lithium Batteries. MUST-HAVE: Easy to use, safe, and fun for your pet. Made by Paws & Pals, an OxGord brand.