Siemens 3SU1150-1HB20-1CA0 — SIRIUS ACT 22 mm command and signalling device. Panel-mount pushbutton, indicator lamp or emergency-stop actuator in the 22 mm cutout family. SIRIUS 3SU1 emergency stop pushbutton, red 40mm mushroom, twist-to-release. 1NC+1NO contact. Positive-opening per EN ISO 13850. Metal front ring. Rated for personal protective equipment duty under the applicable EN, ANSI or ISO standard.