VEI Systems Dual-Display Gauge: Hi-res Vacuum-Boost and wideband air-Fuel Ratio (Orange/Silver) NOTE: currently backordered. Please note significantly longer lead time. &lt; -30 in. Hg to &gt; 90 PSI with 1, 0.5, or 0.1-PSI resolution Includes external fast-response semiconductor vacuum-boost sensor 2-1/16" (52mm) mounting size. Adjustable day and night brightness