This an unflown Model Products Corporation "Miniroc" B3-4 model rocket motor. It is made of pasteboard and contains non-explosive propellant. The "B3-4" 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 it to NASM in 1973.
Gift of G. Harry Stine