DIMENSION MEASUREMENT ---- The head radian is 7.87 inches (20cm) long and the height is 1.77 inches (4.5cm). The head strap ranges from 13.38 inches to 18.11 inches (34cm - 46cm) and the regulation range of the chin strap is between 5.9 inches and 9 inches (15cm - 23cm) (Tension-free measurement). Enjoying dog sunglasses fit over 10lb small to medium dogs eye protection like Poodle, Schnauzer, Hound, Doberman, Corgi, golden retriever, golden shepherd, husky etc, not for tiny, mini pets. ADJUSTABLE STRAP ---- The dog goggles have a high level of elasticity with adjustable length. It is suitable for small dogs and medium dogs. The double strap - the head strap and chin strap enables your dog to wear it in a sturdy way. The goggles don't fall off easily, better protect the dog's eyes. High usage rate regardless of the season, adjustable wearing style, whether daily, travel or party, will be your first choice. LIGTHWEIGHT, SOFT DURABLE ---- The pet sunglasses are formed by UV-resistant PC lens and silicone optical frames, Our doggy sunglasses accord with UV rate standard, lenses are UV-resistant and anti-glare. Translucent black lens provide a not bad field of vision. Your dog feels way comfortable without any burden when wearing our goggles. Not only does it provides a good view for your dog, but the soft framework doesn't damage the fur of your dog's face and eyes. COMFORTABLE TO WEAR WITH VENTS ---- Soft frame pad around inside the sunglasses for comfort and skin-friendly. Spacious interior structure won't press against your dog eyes. Wraparound glasses can stay in the dog's head pretty well without scraping dog's face and eyes. Prevent droplets, dust, tiny stone into puppy eyes when dog stick the head out the window on car, SUV. Protect dogs eyes when they runing, skiing, traveling. They are great hepler for outdoor eye protection. UNIQUE SPECIAL APPEARANCE ----- This pair of dog goggles design is in perfect accordance with the dog's face, so the slightly curved goggles cling to your dog's face precisely. Meanwhile, there are vent holes around the dog glasses that look like comb teeth, these dense holes can quickly dissipate among the heat generated by the dog. improve the safety of protecting dog's eyes.