The Schneider Electric A9D54210 is an Acti9 iC60 RCBO — a combined 2-pole residual-current circuit breaker with overcurrent protection, rated 10 A with a C curve and 300 mA earth-leakage sensitivity.
Breaking capacity is 10 kA Icn at 230 V per EN/IEC 61009-2-1, with an ultimate breaking capacity Icu of 15 kA per EN/IEC 60947-2. That Icu figure tells you the device can safely interrupt a fault once at the higher level — useful for coordination studies where the upstream device clears faster. The C curve trips magnetically between 5 and 10 times In, so for a 10 A RCBO that means instantaneous trip between 50 A and 100 A, typical for general-purpose distribution with moderate inrush (lighting, small motor starters). Earth-leakage protection is integrated at 300 mA sensitivity, covering both poles. The 300 mA threshold is common for protection against fire risk in circuits supplying fixed equipment, not for personal shock protection (which would require 30 mA). Thermal-magnetic trip unit gives you the standard bimetal overload protection plus a solenoid for short-circuits.
Strip length 12 mm for top or bottom connection; tightening torque 2 N·m.