The Siemens 5SJ6316-6RC is a 3-pole miniature circuit breaker from the 5SJ6 Retail line, rated 16A with a B tripping characteristic and a 6kA breaking capacity. It snaps onto DIN rail in a distribution board or sub-panel, protecting final circuits against overload and short circuit per IEC 60898-1.
The B characteristic (3-5x In magnetic trip) makes it suitable for resistive and lighting loads as well as small motor circuits where inrush is moderate — common in commercial and light-industrial final distribution. The 6kA breaking capacity at 230/400 V AC covers typical domestic and commercial fault levels; if your installation has a higher prospective short-circuit current, step up to a 10kA or 15kA rated MCB in the same 5SJ6 family.