Turbosmart's Electric Boost Only Gauge is designed specifically for turbo diesel vehicles. Unlike Turbosmart's mechanical boost gauge which also measures vacuum, the Electric Boost Only gauge measures only boost from 4 Bar. Since diesel engines do not produce vacuum, the Boost Only gauge gives you more accurate boost readings for your turbo diesel vehicle.
Fascia diameter (gauge and bezel) - 57mm Rear diameter (gauge body) - 52mm - See more at: http://www.turbosmartdirect.com/Product-Categories/Gauges/Boost-Gauge-Electric-0-30PSI_3.html#sthash.QFEz4jPu.dpuf
Due to the ever-changing rules around LVVTA standards it is the purchaser’s responsibility to check that these products are compliant with current standards for usage on public roads.