The result was the turret's bearing and elevation orders (LOF). During the surface action, range and deflection Spots and target altitude (not zero during Gun Fire Support) were manually entered. The Mk 41 Stable Vertical was a vertical seeking gyroscope, and its function was to tell the rest of the system which-way-is-up on a rolling and pitching ship. It also held the battery's firing keys. The Mk 13 FC Radar supplied present target range, and it showed the fall of shot around the target so the Gunnery Officer could correct the system's aim with range and deflection spots put into the rangekeeper. It could also automatically track the target by controlling the director's bearing power drive. Because of radar, Fire Control systems are able to track and fire at targets at a greater range and with increased accuracy during the day, night, or inclement weather. This was demonstrated in November 1942 when the battleship engaged the Imperial Japanese Navy battlecruiser at a range of at night. The engagement left "Kirishima" in flames, and she was ultimately scuttled by her crew. This gave the United States Navy a major advantage in World War II, as the Japanese did not develop radar or automated fire control to the level of the US Navy and were at a significant disadvantage. The parallax correctors are needed because the turrets are located hundreds of feet from the director. There is one for each turret, and each has the turret and director distance manually set in. They automatically received relative target bearing (bearing from own ship's bow), and target range. They corrected the bearing order for each turret so that all rounds fired in a salvo converged on the same point. The fire control switchboard configured the battery. With it, the Gunnery Officer could mix and match the three turrets to the two GFCSs. He could have the turrets all controlled by the forward system, all controlled by the aft system, or split the battery to shoot at two targets. The assistant Gunnery Officers and Fire Control Technicians operated the equipment, talked to the turrets and ship's command by sound-powered telephone, and watched the Rangekeeper's dials and system status indicators for problems. If a problem arose, they could correct the problem, or reconfigure the system to mitigate its effect. The Bofors 40 mm anti-aircraft guns were arguably the best light anti-aircraft weapon of World War II., employed on almost every major warship in the U.S. and UK fleet during World War II from about 1943 to 1945.