Vinyl Cap Protectors are glides that go OVER your chair legs. They are designed for chairs which do not have any kind of cup or hollow opening for normal patio glides or inserts. They provide the same kind of protection that normal glides would in preventing scratches on your patio or deck. Made to fit 13/16" legs. To insure a proper fit, measure the OUTSIDE diameter of the patio chair leg and compare it to the dimensions of the patio furniture part dimensions shown in our diagrams. You can find more information about how to measure for patio furniture replacement parts in the FAQ section of our website.