The Triplett TA200-NIST Tachometer provides fast and accurate contact and non-contact Rotational Speed (RPM), Frequency (Hz), Linear Surface Speed (meters per minute, inches per minute, feet per minute, yards per minute), Length (meters, inches, feet, and yards), and Total Revolutions (REV). Features include: wide measurement range with high resolution, laser guided non-contact measurement with 8.2ft (2500mm) maximum target distance, and a backlit 5-digit LCD display. Memory stores last 10 readings for Min/Max/AVG/Data. Includes Certificate of Traceability to N.I.S.T., 2 contact tips/1 wheel, 23” (58.4cm) reflective tape, 9V battery, and carrying case. 1-year warranty.