A4950 is a handheld LED stroboscope for a wide range of machinery maintenance applications. The stroboscope enables the operator to ostensibly stop rotating or generally periodic (reciprocating) motion of a machine. It also allows finding the speed of rotation or performing synchronized measurements without having to use reflective markers on the shaft. The A4950 stroboscope uses three ultra-bright LEDs with an optical system as a source of flashes. The instrument is equipped with a colour graphic display and 3-button keypad. Operation is very easy and intuitive. Two standard or rechargeable AA batteries are used for powering. The A4950 stroboscope can be also used as a tachometer by connecting an external tacho probe.