Check the listing for details. Guyker Open Frame Electric Bass Machine Head (4 Right 4 for Right, chrome. Color: chrome, Condition: New. Listed at 39.10 USD. Guyker Open Frame Electric Bass Machine Head (4 Right 4 for Right, chrome Product Details Item Weight: 10.5 ounces Package Dimensions: 8.15 x 2.32 x 1.97 inches Item model number: 20:1 gear ratio open gear bass tuners Color Name: chrome Number of Strings: 4 Size: 4 for Right Proficiency Level: Professional Precision 20:1 gear ratio with sealed lubrication, cast housings and metal knobs. Mounting hardware (screws, bushings and washers) included. Open gear bass tuning machines for electric bass, like jazz Ibanez style bass, precision bass. Please check the parameter drawing in the attached pics before placing your order. Precision 20:1 gear ratio Guyker guitar bass tuners fit for Jazz bass or precision electric bass. Feature: - Comfortable and easy for adjustment of string tension. - Quality open gear bass machine heads. - Replacement/Upgrade parts for electric bass or precision instruments. - Smooth and shiny, wear-resistant, anti-corrosion, and dust-proof, quick and accurate tuning. - Exquisite appearance with perfect workmanship and high-tech finish. - Provides finer tuning and greater stability. - Complete with color matched threaded bushings, washers and screws. Specifications: - Ratio: Gear Ratio - 1:20 - Style no.: GK-3436 - 3 Colors available: Black, chrome, goldPackage Includes: - GK3436 bass tuners set (4R, 2R2L or 3R2L for choose) - Nut, Ferrule, Screws includedNote: Lubricate the screw threads with cutting lubricant (also wax or a bar of soap) to reduce friction and help them thread properly.