The FEIN 30762555990 Genuine Speed Setting Switch is an original replacement electronic speed-control switch for selected FEIN GSZ11-320PERL and GSZ11-90PERL straight grinders. It works with the machine’s variable-speed system to adjust operating speed and is suitable for replacing a faulty, damaged or failed original control switch. FEIN documentation confirms both models use a six-position speed setting system, while compatibility data shows this exact switch fitted to 110V and 120V machine versions.