The Siemens SENTRON 5SY7620-8 is a 4-pole (3P+N) miniature circuit breaker rated 20 A at 400 V AC with a D tripping characteristic. Breaking capacity is 15 kA per EN 60898 for general distribution and 25 kA per IEC 60947-2 for industrial panel duty; the higher figure governs when the breaker is used as a standalone device in an industrial control panel. The 72 mm width (4 module-width units) snaps into any standard DIN-rail enclosure, and the quick-assembly system means no tools needed for rail mounting — just clip and wire.
The 76 mm depth leaves clearance behind a standard 100 mm deep gland plate; the 70 mm installation depth accounts for the wiring space behind the busbar.