OOK 50221 1/4" Metal Mirror Clips Includes screws and anchors. Since its inception in 1964, OOK Picture Hanging Hardware Co. has developed more innovative picture hanging hardware solutions than any other manufacturer in the world. Our original commitment to museums and art galleries in the 1960âs forged an R & D department focusing on creating solutions for unique, high value, hanging challenges. Many of these new developments became important picture hanging innovations for both professional and consumer alike.