A night-fighter variant of the SM-01, fitted with an experimental RMADS (Radial-Magnetic-Area-Detection-System) to search for magnetic signatures of aircraft engines within 500 meters all-around. whilst the device was claimed to be quite effective, it wasn't without fault; being overwhelmed by storm-clouds and the like. eventually larger Roman planes even had countermeasures added to avoid detection as well. since the aircraft was under-powered, aircrews quickly developed a strategy of attacking vulnerable planes on approach to their bases, until enemy fighters were finally organised to defend their airfields. Regardless, the night fighter did it's job well, and when retired the devices were updated for atmospheric-study as well. for more on the story behind this plane, check out my blog post :)