The RMSAMPS4P 4-Hole AMPS drilled base mount is part of Arkon's Robust Mount Series. It mounts to walls or other solid flat surfaces with screws using the 4-Hole AMPS mounting pattern. This mount is composed of only the Heavy-Duty 4-Hole AMPS Mount with a 4-Prong Head. This mount measures 4.25 inches tall from end to end and is ideal for tight areas where a smaller pedestal is beneficial. The mount is compatible with 4-Prong mounting pattern compatible device holders, cradles, adapters, and other components (sold separately). This tough, low-vibration mount shaft is made of composite. The double-socket mount shaft arm swivels on both the top and the bottom, providing 360-degree rotation and the ultimate flexibility in positioning the mounted device at any angle. The 4-Hole AMPS pattern consists of four holes located in a rectangular pattern spaced at 30.17mm x 38.05mm (measured as the center-to-center distance between holes). The mount can also be screwed directly into the floor of your vehicle. (Warning: Drilling into the vehicle's floor may damage the vehicle. Use caution and consult a mobile install professional to avoid drilling into any sensitive vehicle components.)