The triple square square round three light pole mounting bracket is designed to be slidable onto the 2-3/8' tenon. Can also be used for sliding installation of 2-7/8 and 4 tenons. The typical application of the triple round square pole lamp bracket is on wood, steel and concrete poles. Comes with a removable cover and assembled fixing hardware. Provide hot dip galvanized (HDG), dark bronze, black, dark gray, white or natural aluminum surface coating. Optional horizontal installation. 4" square column bracket, carbon steel, shiny bronze/base: 3 screws Holes for 3/8" -16/Tennon: 3x vertical tenon, 180D, OD60x HT4