Salvaged vintage lamp Parts , Great lamp repair and restoration supply. 3 3/4 inch in diameter , with a 1 3/8 central opening , approximated 1/2 inch deep . These beautiful cast metal lamp parts are meant to screw onto the threaded uno sockets on some earlier lighting models . They were to give a more finished appearance as well as beautify the lighting fixture. the lovely pierced inner border , and the silver tone back ground in picked out colors of red and green , lend to the charm of these pieces. As these are salvaged items They are old and in these parts case the original finish is showing its age . Lovely if your wanting an aged look all around , how ever if you are of the mind set to bring your project to looking new , These would be easily cleaned and recolored .