The C curve means magnetic trip between 5× and 10× In — about 80–160 A instantaneous — so it won't nuisance-trip on the starting surge of a 4 kW motor or a bank of LED drivers. The Type AC residual current detection picks up sinusoidal AC earth faults only; if the load has VFDs, switched-mode supplies, or rectifiers that generate pulsed DC fault currents, you need a Type A or F device instead. The 16 A rating is at 30 °C ambient; at 40 °C it derates to 15.2 A, at 50 °C to 14.4 A, and at 70 °C to 12.32 A.
The IP20 rating assumes the distribution board is installed with connected conductors; it's not a standalone outdoor device.