This is an injection-plastic jet aircraft model kit.
From the manufacturer:
Developed as a small, lightweight and maneuverable fighter, the Folland Gnat was never accepted into RAF service in that role. However, after being re-designed with two seats, it found its niche as a superb trainer and its small size and excellent aerobatic capability made it a natural choice for the RAF's aerobatic teams. The Yellow Jacks first used the Gnat to great effect, before the REd Arrows used it as their first aircraft.
Completed model measures 230mm long and 153 wide.