Aluminum alloy, anodized, 1.500 in. W across flats, 0.781 in. H, 1-1/4-18unef-3b thd located one end 0.469 in. Max deep, 1.255 in. Diameter internal groove located 0.190 in. From opposite end, 1.125 in. Id between groove and end opposite thd end, one 0.136 in. Diameter hole from groove to flat