The Shimpo dt-105a-s12 portable contact Tachometer has a 12-inch wheel, measures rotational speed, linear speed, surface speed, and total Length, and provides 16 different measurement units for rate and speed. This portable contact Tachometer has a 12-inch wheel and is used for measuring the speed of motors, conveyor belts, and other moving and rotational systems. It measures rotational speed, linear speed, surface speed, and total Length for flexibility of use, and measures the rate of speed and Length in 16 different units for versatility. The five-digit LCD screen presents Test results and the unit of measurement. Flashing numerals on the LCD screen indicate speeds outside of the measuring range to help avoid damage to the instrument. It stores up to 13 readings, including the maximum, minimum, and last Test result values for ease of data recall. A die-cast aluminum body provides durability in harsh environments, and the device can be tripod-mounted and locked to take continuous measurements. The Tachometer conforms to NIST standards for compliance with regulations, and the CE mark indicates compliance with applicable EU Directives. It comes with a 12-inch wheel, two cone adapters, a funnel adapter, a 3.5-inch extension shaft, a carrying case, and an NIST certificate. This Tachometer is suitable for measuring rotational speed and other measurements in mechanical or industrial engineering environments.