Frame Dimensions: Borderline: 8, Diameter: 2. Convertible borderline of head strip:13.5-18, convertible borderline of chin strap: 6-9. Before buying this dog goggle kindly measure out your dog head and chin size. Good Quality material: 2 adjustable elastic straps on the dog sun glasses with ultra hard PC and UV resistant lens for small to medium dog like Corgi, Shiba Inu, Beagle, Medium-sized Poodle, not recommend for little Chihuahua. Vents on frame: Glasses for dogs are made of spongy design frame which can give relaxing and roomy experience to your dog, and there will be no water mist on the lens. Ultra hard lens: Lens are the production of high-quality polycarbonate which give convenient to your dog eyes not just from UV, Infra red rays but also compete with dust particles, wind and so on. Effortless to wear: Dog sunglass head and chin elastic bands are very flexible and adjustable to wear and it is acceptable for small and medium-sized dogs.