What it is and where it fits
The Siemens 5SN2-340 is a DIN rail mount miniature circuit breaker (MCB) from the 5SN2 series, used for overcurrent and short-circuit protection in distribution boards and control panels. Snaps onto standard 35 mm DIN rail, so it integrates directly into a panel's existing protective device layout without extra adapters.
Lifecycle and sourcing reality
The 5SN2-340 carries a current production lifecycle stage — it remains in active manufacture and is sourced through standard Siemens distribution channels.