The A9L16299 is a Type 2 + 3 surge arrester from the Acti9 iQuick PRD family, designed for electrical distribution networks. The pluggable cartridge means you can replace the MOV module without pulling the base off the DIN rail — useful when the cartridge has taken a hit and the base and signalling contacts stay in place.
Rated for 400 V AC (+/- 10 %) at 50/60 Hz, with a maximum continuous operating voltage (Uc) of 350 V L/PE in common mode. That 350 V Uc is the voltage the MOV can sit across continuously without degrading — important in TN-C or IT 230 V earthing systems where the phase-to-PE voltage can be higher than 230 V. The protection level (Up) is <1.2 kV in common mode for Type 2, which means the equipment downstream sees no more than 1.2 kV across L-PE during a surge. Nominal discharge current is 2 kA per mode (common and differential); maximum discharge current is 8 kA common mode — that's the single-shot survival rating, not the repetitive duty.
Clip-on mounting to DIN rail. The 3-pole footprint takes 12.7 mm of 9 mm pitch modules — so three poles at 12.7 mm each. Depth is 75.9 mm, height 94 mm, width 113.6 mm. Tunnel-type terminals on both top and bottom accept 2.5 to 25 mm². Tightening torque is 2.5 N.m. The remote signalling contact (1 C/O, rated 2 A / 250 V AC) lets a PLC or building management system see the cartridge status without walking the panel.