Koso North America GP-Style Universal Tachometer w/ Temperature Gauge - White Background BA551B23 Easy-to-read white background with blue backlight Stepper motor keeps dial needle stable through the heaviest vibrations Gauge dial shows tachometer with 0-9000 rpm range; adjustable by units of 100 rpm Blue-backlit digital display shows water temperature Gauge measures 55mm dia. without bezel; 61mm dia. with bezel