https://www.ebay.co.uk/itm/New-Motorcycle-Carb-Carburettor-Vacuum-Balancer-Gauge-2-4-Cylinder-Gauges-Kit/401517479725?hash=item5d7c4e872d:g:1AwAAOSwWxxaxLI've a set of these budget Vac gauges, dropped my expensive "Davida" set.These work as well any Vac gauges, not silly money either ..