Paws & Pals LED Pet Neck Collar Flashing Color Light Up Night Safety Strap, Large, Red 4 modes: On, Off, Normal Flashing, and Fast Flashing Includes 2x CR2032 Batteries Made of Nylon for Superb Durability Fits neck circumference, 21" max, 16" min 4 modes: On, Off, Normal Flashing, and Fast Flashing Made of Nylon for Superb Durability Fits neck circumference, 21" max, 16" min