This sturdy mount includes Lido's EXT-01 mounting plate with the LM-500DB 4-Hole AMPS Mount. In addition to Ham Radios you can attach marine electronics, you can attach other accessories including batteries, CB radios, and audio receivers. The plate can also be used as a splitter plate. The anodized machined aluminum plate measures 6.75” (17mm) long, 2” (50mm) wide, and 4mm thick. It features a pre-drilled hole for Yaesu 5mm bolt and a predrilled hole for the Icom 14/ X 20 bolt. It also has 48 4mm unthreaded holes that are spaced apart to provide a number of mounting options, including multiple 4-Hole AMPS devices. The four 5mm holes in the center of the plate are also recessed in the 4-Hole AMPS pattern. The 4-Hole AMPS pattern consists of four holes located in a rectangular pattern spaced at 30.17mm by 38.05mm (measured as the center-to-center distance between holes). The tough, low-vibration mount pedestal measures 6.5 inches high and is made of a combination of plastic and glass fiber. It features an AMPS drill mount base. The arm of the pedestal swivels on both the top and the bottom, providing 360-degree rotation and the ultimate flexibility in positioning the device at any angle.