Siemens 3SK1112-2BB40 — SIRIUS 3SK1 safety relay. Compact safety relay for emergency-stop, safety-gate and light-curtain monitoring per EN ISO 13849. SIRIUS 3SK1 safety relay basic unit with 2 enabling paths + 1 signaling. PL e / Cat 4, SIL 3. For emergency-stop and two-hand control. Installed in low-voltage switchgear panels, main and sub-distribution boards, motor control centres and DIN-rail consumer units.