3 decal variants:
1. SAI 207 - MM 8431, seventh production machine
2. SAI 207 - MM 8433, in nothern Italy with German insignia
3. SAI 207 - MM 8436 of the 3 Sormo at Cervateri in Summer 1943
Steffanuti designed the aircraft to have a lightweight structure and light armament to allow lower-powered engines to be used, without unduly reducing performance. The first of three prototypes was completed and flown in the Autumn of 1940 as the sole SAI.107, which was a minimum change fighter development of the SAI.7, with identical dimensions, apart from length, at 8.02 m (26.31 ft) and the 402.7 kW (540 hp) Isotta-Fraschini Gamma engine. Weighing only 1,000 kg (2,205 lb) the Sai.107 reached a speed of 563 km/h (350 mph) in trials held at the Guidonia research establishment and manoeuvrability proved to be excellent. The SAI.107 was lost, along with pilot Arturo Ferrarin, in a crash on 18 July 1941.