Material: aluminum strip SBR foam Function: if a pet with poor eyesight encounters obstacles in front of him when walking, the collision ring will feed back to the pet when encountering obstacles, so as to avoid accidental injury caused by PET collision. Collar and bust dimensions can be adjusted. Product size: S = ring diameter 22CM(for 4-10kg) M = ring diameter 33 CM(for 13-20kg) Using this halo will not affect eating, sleeping or daily activities for your dog. Lightweight and easy to use, the halo is attached to a vest harness, so your dog can wear it easily; and comes with buckles, which can prevent the dog from breaking free. Made of soft fabric and aluminum strip, comfortable for your dogs to wear. Impaired eyesight will dampen the dogs confidence in walking, which will result in the dogs reluctance to move. Using our products allows dogs to walk with confidence and rebuild their confidence. The protection ring is specially designed for dogs with impaired vision, which can protect your dog from collisions with surrounding objects.