UDTEE Durable/Practicle Green/ Blue/White/Red/Pink/Orange/Yellow/Rainbow Color Nylon LED Light Flashing Pet Dog/Cat Safety Collar(Size:Small,Medium,Large,X-Large) Neck Size:L:42-60cm;2.5cm collar width Must-have safety collar helps incoming cars and traffic see both you and your pet in the dark. Made of fiber optic and nylon fabric for maximum durability and protection from water. Lightweight and comfortable for your dog. How to measure your dog's neck size: measure around the neck close to the shoulder and allow room for a comfortable fit.