Gauge May Be Mounted In 2"/52mm Dia holes Or In Auto Gauge Custom Mounted Panels. Attach Nylon Pressure Line To Fitting On Back Of Gauge Using Adaptor ,Ferrule ,And Compression nut. Connect Line To Pressure port On Engine By Using 1/8" Adaptor Ferrule And Compression Nut For Turbo And Prossure Gauge Or 1/8" Adaptor And Fitting For Vacuum Gauge.
eBay