Tanabe 1TR1AA005 Revel VLS Wideband Air/Fuel Ratio Gauge, 52mm 52mm diameter gauge 10.0:1 to 20.0:1 AFR reading Bosch 4.9 LSU sensor Digital OLED display; 30 LED outer ring Mounting kit included; Tanabe 1TR1AA005 Revel: VLS Wideband Air/Fuel Ratio 52mm Gauge