The Siemens SIRIUS 3RV1926-0J is a toggle-style selector extension designed for circuit breaker sizes S0, S1, S2, and S3. It extends the rotary or toggle operator to the enclosure door or panel face, letting an operator manually reset or switch the breaker without opening the panel. The part is listed with lifecycle stage "current" but carries a phased-out notation — the manufacturer's successor is the SIRIUS 3RV2 series.
The 3RV1926-0J is still designated as current-production lifecycle stage, but the manufacturer explicitly marks it as a phased-out product with the SIRIUS 3RV2 as the successor. That means new-build panels should spec the 3RV2 equivalent; for existing panels with a 3RV1 breaker, this extension remains the correct drop-in replacement.
This extension mounts to the front of the 3RV1 circuit breaker and passes through the enclosure cutout. No rewiring involved — it's purely mechanical.