This altimeter was one of the standard instruments onboard the Piper Cub J-3 and L-4 aircraft. Designed by C.G. Taylor in 1931 to be economical and easy to fly, the Cub had only four instruments: an altimeter, a tachometer, an oil temperature gauge and pressure gauge.
The Cub's simple design made it extremely popular among beginner pilots. By 1941, a third of all general aviation aircraft were Cubs, and more than 27,000 had been sold when production ended in 1947. The Cub's popularity was due in large part to the marketing genius of William Piper. He made sure the airplane's famous bear cub logo appeared in a variety of places: magazines, posters, souvenirs, pennants, and even on the aircraft's instruments.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.