ITEM NAME:2x Motorcycle Carburetor Synchronizer Vacuum Gauge Tool Sync Gauge for Yamaha Description: Brand New and High Quality Excellent quality vacuum gauges enable easy synchronisation and balancing of motorcycle carburettors. Each gauge has damping control and calibration control. Easy to install, instructions is not included. Specification: Material: Plastic Diameter: 70mm/2.8 inch Height: 25mm/1 inch Package Includes: 2 Pieces Carburetor Vacuum Guage.2 Pieces Carburetor Vacuum Guage. Excellent quality vacuum gauges enable easy synchronisation and balancing of motorcycle carburettors. Easy to install, instructions is not included.