Standard Support w/4-Way Base w/Spacer & 1.5" CollarA perfect blend of form and function, Antenna Mounting Systems by Rupp combine good looks with innovative designs. The locking collar holds antenna securely, yet unlocks conveniently for lowering. Made of forged and anodized aluminum for strength and long lasting beauty. Standard supports are designed for easy mounting to cabin sides. Features: Base: Oval 4-Way Spacer: 4.5" Bolts: 2-6"