The Siemens 5SU9326-1CS50 is a 2-pole RCBO from the SENTRON series — an RCD-operated circuit breaker that combines overcurrent protection and residual current detection in a single 4-width-unit package. It's rated 50 A at 30 °C with a 30 mA trip threshold and a C-curve tripping characteristic, meaning it handles moderate inrush from motor or lighting loads without nuisance trips. Breaking capacity is 6 kA per both EN 60898 and IEC 60947-2, which covers most residential and light commercial distribution boards.
Installation depth is 70 mm, with overall dimensions 77 mm deep, 72 mm wide, 90 mm tall. The neutral conductor is switched internally (product function neutral conductor switching yes), so it's a true 2-pole disconnect. IP20 with the distribution board installed and conductors connected — fine inside a closed enclosure.