The Siemens 5SJ6220-7CC is a 2-pole miniature circuit breaker (MCB) with a C-trip curve, rated 20 A at 400 V and a 6 kA breaking capacity. The 70 mm tall housing fits standard DIN-rail enclosures.
The 2-pole footprint occupies two module widths (roughly 36 mm). Panel builders should account for thermal derating when grouping multiple MCBs in an enclosure—the 20 A rating assumes 30 °C ambient; higher ambient or tight packing reduces the continuous current capacity.