The M621 is a 20 mm automatic cannon of French design, developed by Nexter as on-board armament for armored vehicles, aircraft, helicopters and small coastal vessels of the French Navy.

[1] Cannon pod for helicopters and light aircraft.

[2] Remotely controlled weapon station with M621 and a 7.62×51mm machinegun.

[5] As remote-controlled naval gun on the Nexter Narwhal 20A.

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