MAXRAD 0-6,000 MHz brass 3/4" hole mount only. Purchase cable and connector seperately. 1. Mounting hole size: NMO & SM : 3/4" MA & MATM: 3/8" or 3/4" MTPM: 5/8" 2. Route cable from the inside of the vehicle and feed mount through hole. 3. Insert lubricated o-ring in groove on the underside of the coupling nut. 4. Tighten coupling nut over mount. Additional Model #'s 221-NMO34 NMO34 UPC: 888063324840