Compact instruments tachometer android APP is designed for using with MiniVLS313 tacho laser sensor produced by compact instrument Ltd. Your smartphone must support USB on-the-go function. MiniVLS313 USB Tacho sensor is the first pocket laser tachometer to measure RPM for android smart phone tablet or PC with data save function. It can be used to measure, monitor and save RPM data.It features comprehensive specifications including maximum, minimum speed, average speed display, sampling time option, different unit option and diameter setting for linear speed.