Slotted mounting holes mount 2-3/4" and 3-9/16" center to center
Heavy duty offset crossbar measures 4-3/8" long x 1 1⁄4" wide, .08" thick, tap 1/8F middle. Crossbar has 8-32 ground screw inserted in hole. Slotted mounting holes will mount 2 3⁄4" & 3-9⁄16" center to center.