1Applicable Rails: Base measures standard 114in male thread, recommended for installation on 2225mm (7 or 81in) vertical, horizontal or oblique rails. 2316 Stainless Steel: Constructed corrosion resistant investment cast 316 stainless steel, has good wear resistance in humid air or high temperature weather. 3With Lever Handle: This ratchet rail antenna base features a lever action handle that makes lowering the antenna quick and easy for passing under trailering. 4Adjustable Ratchet: The antenna base has 2 adjustable ratchets, the upper ratchet can be adjusted to 270 degrees, the lower ratchet can be adjusted to 180 degrees. 5For Marine Use: The VHF antenna mount is suitable for boats, yachts, RVs, etc., it has a compact structure and standard size, which is easy to install and replace. Item Type: Marine VHF Antenna Mount Product Material: 316 stainless steel, mirror polishing Thread Diameter: 1in Applicable Rail Diameter: 22-25mm (7 or 8-1in) Features: The antenna base has 2 adjustable ratchets, the adjustable angle of the upper ratchet is 270 degrees, and the adjustable angle of the lower ratchet is 180 degrees Applications: Boats, yachts, RVs 1 x Marine VHF Antenna Mount