Install GPS & VHF antennas above the radar for maximum visibility and performance All mounting holes predrilled for easy retrofit installation, attach using mounting bolts, no extra fastenings required Cables run internally via a watertight seal Mount starboard side of the radar antenna Marine-grade 316 stainless steel Designed for the installation of GPS antenna andWhiptype VHF, HF/SSB, AM/FM, and cellular antenna of up to 1m in height - must have standard 1x 14TPI thread as their fixing. They are also designed to work with Pacific Aerials P6161 / P6162 adapter for their Pro range of antennas.