The Extech 461895 is a versatile dual-mode tachometer that combines contact and non-contact (photo) RPM measurement in one handheld unit. Ideal for industrial maintenance, automotive, and HVAC applications, it measures rotational speed from 0.5 to 20,000 RPM via contact tip and 5 to 99,999 RPM using a photo sensor with included reflective tape. Features include 0.05% accuracy, 5-digit LCD with mode-based display orientation, Max/Min/Last memory, and linear surface speed measurement in ft/min or m/min.