Used MFJ-335BM SN55083
5" Magnet Mount Assembly -- NMO + 17 FT of RG-58, to PL-259
Medium to Heavy duty magnet mount. Super strong 5 inch diameter base weighs a husky 2 1/2 pounds. For medium to large size antennas. It's perfect for MFJ's RuffRider series of Super Gain mobile antennas. NMO Style connector.