It measures approximately 11.5". Be sure to measure your pet for perfect fit. Keep your furry family members safe and stylish with our Glow in the Dark Collar for Cats and Dogs! Featuring a luminous design and a cute cat face charm, this collar provides enhanced nighttime visibility and a fun look. Made of a durable material and with an adjustable fit, it's perfect for outdoor pets. Measures 11.5" and comes in various colors. (Make sure to measure your pet for a perfect fit! And for even more brightness, use a flashlight!)