This is an unflown Eastern Ballistics B4-3 model rocket motor made of pasteboard and containing non-explosive propellant. The "B4-3" signifies that the power of the motor is in the second lowest class (out of seven) established by the National Association of Rocketry. A motor is used only once to power a model rocket. G. Harry Stine, a pioneer in the field of flying rocket models, donated this artifact to NASM in 1973.
Gift of G. Harry Stine