A perfect blend of form and function, Antenna Mounting Systems by Rupp combine good looks with innovative designs. Patented locking collar holds antenna securely, yet unlocks conveniently for lowering. Made of forged and anodized aluminum for strength and long lasting beauty. Rupp Antenna Mounting Systems are available in two styles: standard supports designed for easy mounting to cabin sides, and threaded supports ideal for tuna towers and tops. Both styles are made to fit 1? or 1 1/2? diameter antennas.