AlphaMoto Vacuum Carburetor Synchronizer Carb Sync Gauge Gas Tank Cb Kz Gs 550 650 750 This listing is for one auxiliary gas tank and one 4 cylinder carb synchronization gauge auxiliary gas tank is used when tuning a motorcycle with the gas tank removed This vacuum gauge set features 4 precision gauges. Each gauge has its own individual damping control and Calibration Control The gauge is universal tool, it contains 5mm adapters for Honda, Suzuki, and 6mm adapters for yamaha.