application: applicable to the product departments of motor, fan, paper-product, plastics, chemical fiber, washing-machine, automobile, airplane, steamer etc. dt-2856, dt-2857, dt-2858, dt-2236, dt-838c, dt-2234a, dt-2234c, dt-838.dt-2235a features: 1,measuring rpm is safe & accurate without attachment to object. 2,wide measuring range & high resolution. 3,digital display gives exact rpm with no guessing or errors. 4,used the exclusive micro-computer lsi-circuit and crystal time base to offer the high accuracy measurement & fast measuring time. 5,the last value/max. value/min. value will be automatically stored in memory and can be displayed by turn. 6,the use of durable, long-lasting components, including a strong, light weight abs-plastic housing assures maintenance free performance for many years. the housing has been carefully shaped to fit comfortably in either hand. tachometer(photo/touch type) dt-2856 product synopsis model: dt2856 measuring range: rotative velocity laser 2.5-99999r/min contact 0.5-1999r/min laser tach detecting distance: 50-600mm accuracy: ±(0.05%n+1d) resolution: 0.01/0.1/1 memory: max/min/last value power supply: 4x1.5v aa (um-3) battery battery indicator: low battery indicator dimensions: 220x75x29mm weight (not including probe):171g