Messerschmitt Bf-110 G4

The Messerschmitt Bf 110 G-4 was used extensively by the Luftwaffe as the primary radar-equipped night fighter for defending the Reich against Allied bomber raids later in World War II (roughly 1943-1945). It operated across European theaters, including Germany, Northern Finland, and with Italian forces (ANR). 
 
Key Operational Details:
Primary Role: The G-4 variant was the final production model, specialized for night interception of Allied heavy bombers, equipped with Lichtenstein radar.
Theaters: It was heavily deployed over Germany to defend against night raids, and also saw service in Northern Finland (e.g., 13./JG 55), the Mediterranean, and with the Italian National Republican Air Force (ANR) in 1944.
Effectiveness: It became the backbone of the German night fighter force (Nachtjagd).
Weaknesses: Despite its improved armament and engines, the G-4 faced declining effectiveness against superior Allied aircraft later in the war. 
 
The aircraft was also used as a heavy fighter-bomber in various theaters before focusing on night fighting.