Digi-Sense, 20250-26, Digital Contact/Photo Tachometer with NIST-Traceable CalibrationFeatures with all optional accessories:Reliable measurements, guaranteed! Precalibrated to NIST-traceable standardsMicroprocessor-based design provides precision accuracy of ±0.05%User-selectable contact or photo configurations for wide range of applicationsEasily view max, min and last value for quick interpretation of resultsStores up to twenty last average measurements for additional flexibilityMeasure from a distance up to 19-11/16" (50 cm) in photo tachometer mode, ensuring operator safetyLarge easy-to-read backlit display is perfect for poorly lit environmentsDurable, lightweight ABS plastic housing is ideal for industrial environmentsIncludes:contact convertersurface speed wheelrpm contact adapterlarge male rpm rubber conesmall male rpm rubber conefemale rpm rubber cone, reflective tape (23-5/8", 60 cm)four set screws, carrying case, four AA batteries and NIST-traceable calibration.The Digi-Sense digital contact/photo tachometer is designed for quick and accurate rpm and surface speed measurements on fans, motors, turbines, gears, conveyors, rollers, shafts and cams, spindles and more. This essential instrument in predictive and preventive maintenance programs lets you identify potential issues early, reducing costly downtime and repairs and keeping your equipment running smoothly. Easily configure the tachometer for either contact or noncontact measurements depending on your application requirements. Use the included adapters in contact mode for quickly taking measurements; take measurements from a distance when in photo mode for use on dangerous running equipment. Features include max, min and values stored, auto-ranging, built-in memory recall of up to twenty last average measurements and a rugged, lightweight ABS plastic design that fits comfortably in your hand for extended use. Plus the NIST-traceable precalibration means you get reliable measurements right out of the box, saving you time and money!.