It is rated for 230 V AC, 50/60 Hz, with a B tripping curve and a 6 kA breaking capacity per IEC/EN 60898-1.
The B-curve trips between 3 and 5 times rated current — so for a 20 A MCB like this one, magnetic trip happens between 60 A and 100 A. That makes it a good fit for resistive or general-purpose loads where you don't have high inrush (lighting, socket circuits, small appliances). If you were protecting motor loads with higher starting current, you'd want a C or D curve instead. The neutral pole switches as well, which is a nice safety feature — when the breaker trips, both conductors are opened, not just the line. The 10 000 mechanical operating cycles typical is fine for a distribution board that sees occasional switching; if you're cycling it daily as a disconnect, that number is still adequate for years of service.
The 18 mm width is a single modular unit; if you need to add auxiliary contacts or shunt trips, the product extension is supported (the listing confirms installable supplementary devices). Terminals accept standard copper conductors; no combined top/bottom terminal, so incoming and outgoing are separate.