Product_description: ['"The Series DT-105A Tachometer with microprocessor technology has heralded a superior standard in tachometer accuracy and capabilities for measuring and recording speeds of rotational, linear and surface plus total length. -Outstanding Accuracy allows use in the strictest applications -Sophisticaed laser beam detection up to 20 feet provides operator safety -Exceptionally rugged die-cast aluminum housing -10 Measurement memory capacity allows quick retrieval of stored data -Long lasting battery life up to 40 hours -Rear Threaded inserts provides option to permanently mount the device. -CE Mark and NIST Certification included provide guarantee of quality performance Offering unprecedented confidence, the DT-105A battery-operated tachometers feature the same rugged, high quality components that have made them the benchmark in the industry. These user-friendly, value-packed units feature memory storage -quick adjustment units knob -length functions -retrieval of last, maximum and minimum values -plus each unit comes standard with a free N.I.S.T. certificate. Units are available with an LCD or vibrant red LED display.Incorporating the precise technology and user-friendly functions as the DT-105A, the DT-105A-S12 provides an exceptional accuracy in measuring speed and length via its 12 wheel. The larger wheel rotates more slowly than a standard 6 wheel, enabling reliable and safe registration of high speeds. "'] (Page 1)