Upgrade your 4-string bass with open-gear tuning machines built for smooth and precise tuning control. The Guyker GB530T features a 1:28 gear ratio, carbon fiber styling, and multiple layout options for bass replacement, repair, and custom build projects.

Key Features

• 1:28 gear ratio: Provides fine tuning adjustment for accurate bass tuning control.
• Open-gear non-locking design: A classic bass tuner structure suitable for replacement and upgrade projects.
• Carbon fiber styling: Combines a modern visual appearance with aluminum alloy construction and copper gear components.
• Multiple layout options: Available in 2R+2L, 1R, 1L, 4R, and 4L layouts to match different bass headstock configurations.
• Fitment reminder: Please confirm your bass peg hole diameter, mounting screw positions, post size, and bushing dimensions before ordering.

Technical Specifications

SKU / Model	GB530T
Product Type	Bass Tuning Machines
Tuner Type	Open-gear, non-locking
Suitable For	4-string bass
Gear Ratio	1:28
Color / Finish Options	Gold, Chrome, Black
Layout Options	2R+2L, 1R, 1L, 4R, 4L
Material	Carbon fiber, aluminum alloy, copper gear
Required Peg Hole Diameter	14 mm
String Post Diameter	14 mm
Overall Length	100 mm
Backplate Size	48.3 x 46.7 mm
Button Size	46.8 mm
Upper Mounting Hole Spacing	28.9 mm
Lower Mounting Hole Spacing	25.6 mm
Vertical Mounting Hole Spacing	37.8 mm
String Post Slot Width	4 mm
Bushing Size	21 mm flange OD, 18.7 mm body OD, 9 mm height
Package Includes	Varies by selected layout option

Compatibility Notes

Important: Please confirm your bass guitar’s peg hole diameter, post height, bushing size, and mounting screw position before installation. Guitar models may vary by production year, factory, and region.

Package Includes

• Package quantity varies depending on the selected layout option.
• 2R+2L option: 2 x right-side bass tuning machines and 2 x left-side bass tuning machines with matching bushings and mounting screws
• 1R option: 1 x right-side bass tuning machine with matching bushing and mounting screws
• 1L option: 1 x left-side bass tuning machine with matching bushing and mounting screws
• 4R option: 4 x right-side bass tuning machines with matching bushings and mounting screws
• 4L option: 4 x left-side bass tuning machines with matching bushings and mounting screws

Installation Note

Before installation: Compare the product dimensions with your original tuning machines to confirm compatibility. Minor modification may be required depending on the bass model, production year, or existing hardware.

Size Reference

Important: Please refer to the size chart below and compare all dimensions with your original part before ordering.