Classic Triumph / BSA Oil Pressure Gauge Kit Includes Gauge 0-100PSI, Pipe & All Fittings - Speedometer & Tachometer from Classic Bike Parts Cheshire UK
FAQ: My liquid filled gauge isn't reading correctly, do I have a faulty gauge?
Marshall 1.5" Direct Mount Liquid Filled Fuel Pressure Gauge, Silver, LS00100 | eBay