Product Size: The upper part of the curve where our glasses fit snugly on the dog is 7inch, corresponding to the top of the head. The lower part of the curvature is 4inch, corresponding to the bridge of the nose. The product has a certain bending flexibility, so we believe it will fit perfectly. Adjustable Strap: Lens outer curvature size 9.5*3.75inch, headband adjustment size 13.4~20inch, chin strap adjustment size 6.3~9.5inch. with fixed adjustable strap, it can adjust the size according to the dog's needs. Premium Material: The lens is made of PC material, the frame is made of soft TPU material, and the side that contacts the dog has a foam pad. UV Protection. Functionality and comfort coexist, and dogs will not feel tired after wearing them for a long time. Protect Dogs Eyes: Get your dog a pair of sunglasses to keep his eyes protected during the sunny summer days. Dogs are less likely to get their eyes hurt by other things when they stick their heads out of the window while driving. Exquisite Packaging: Dog glasses comes with sophisticated packaging. It can be used as a gift for dog lovers. At the same time the packaging can better protect the glasses, not easy to damage in transit.