I-16 Type 10 - Four 7.62 mm ShKAS machine guns (two synchronized in the fuselage and two in the wings), windscreen replaced the sliding canopy, could be fitted with retractable skis for winter operations, M-25B engine with 560 kW (750 hp).
I-16 Type 18 - Type 10 with Shvetsov M-62 engine producing 620 kW (830 hp), with a two-speed supercharger and a variable-pitch propeller. Capable of carrying two 100 L (26 US gal) underwing fuel tanks.
I-16 Type 24 - Four 7.62 mm ShKAS machine guns, upgraded to Shvetsov M-63 engine with 670 kW (900 hp), landing flaps replaced drooping ailerons, added tailwheel & second cockpit door on the starboard side, can carry RS-82 unguided rockets.
I-16 Type 28 - Type 24 with two 7.62 mm ShKAS achine guns & two 20 mm ShVAK cannons.