Tachometer Eatures: Measuring rpm is safe & accurate without attachment to object. Wide measuring range & high resolution. Digital display gives exact rpm with no guessing or errors. Used the exclusive micro-computer lsi-circuit and crystal time base to offer the high accuracy measurement & fast measuring time. The last value/max. Value/min. Value will be automatically stored in memory and can be displayed by turn. The use of durable, long-lasting components, including a strong, light weight abs-plastic housing assures maintenance free performance for many years. Product synopsis Model: dt Measuring range: rotative velocity laser . - r/min Contact . - r/min Laser tach detecting distance: - mm Accuracy: f+( . %n+ d) Resolution: . / . / Memory: max/min/last value Power supply: x . V aa (um- ) battery Battery indicator: low battery indicator Dimensions: x x mm Weight (not including probe): g