The Siemens 5SM3316-0KL is a SENTRON residual current circuit breaker (RCCB), 2-pole, Type AC, rated 63 A at 230 V AC with a 30 mA trip threshold. The RCCB is instantaneous (no intentional delay), so it trips on any residual current above 30 mA without a time delay. That's the right choice for circuits where you want immediate disconnection on a ground fault — general power outlets, lighting, and small equipment. If you needed delayed tripping to coordinate with downstream RCDs, you'd look at the SENTRON 5SM6 series instead.
The housing is 2.5 width units (each 18 mm, so roughly 45 mm wide) and the installation depth is 70 mm — check your enclosure depth before committing. The neutral connection is on the left (N left variant), which matters when you're laying out the busbar or wiring order in a multi-row panel. Supply can come from top or bottom, so you're not locked into a specific feed direction. Terminals accept solid or stranded conductors from 1.5 mm² up to 25 mm², with a recommended tightening torque of 2.5 to 3 N·m. That range covers everything from 1.5 mm² lighting circuits up to 25 mm² main feeders — no need for a separate adapter or reducer.