Liquid Crystal Display (LCD) tachometer model 8905. LCD tachometer is backlighted with red LEDs and ideal for use in direct sunlight. Available with or without digital engine hour-meter. Available with polished stainless steel bezel (P) or black anodized aluminum bezel (B). SM & SH versions designed to be used with magnetic sensor or other type of sensor on flywheel, cam gear or similar gear tooth item. SM (Switchable Medium) version can be calibrated to "sense" slide by of 17-90 gear teeth. SH (Switchable High) version can be calibrated to "sense" slide by of 91-255 gear teeth. Standard (non SM or SH Version) used on gas engine or on diesel engine with a mechanical sender.