461895 Combines both contact (0. 5 to 19,999 RPM) and non-contact (5 to 99,999 RPM) models for use in virtually all tachometer applications. Uses visible light for non-contact measurements up to 6 in. (150 mm) from target. Comes with wheels for linear surface speed (0.2 to 6560 ft. /minute; 0.05 to 1999.9 m/minute) or RPM measurements, 4 AA batteries, 23 in. (0.6 m) reflective tape, carrying case, and user manual.