Forced-guided coupling relay in an industrial housing 1 normally open contact / 1 normally closed contact (24 V) 24 V DC SIL 3 / PL e screw connection Forced-guided coupling relay SIRIUS 3RQ1 for fail-safe coupling of control signals from and to a controller and for contact extension of 3SK safety relays. This forced-guided coupling relay 3RQ1 has safety certification and can be connected to 3SK safety relays using device connectors with minimal wiring. Removable terminals enable easy device replacement and fast wiring. Devices are available with safety certification up to SIL 3/PL e, with single and wide voltage ranges, various contact designs, also in a width of 17.5 mm, each with screw or spring-loaded connection (push-in). SIRIUS relays - a program for all cases.