Big Boom Carbide Cannon Operates on the same principle as a gas engine in an automobile, using gas, fresh air & a spark. Powdered calcium carbide "ammo" is added to the water in the chamber of the cannon. Auto flint firing mechanism creates the spark to give perfect combustion. Produces a realistic flash & boom. Metal w/ heavy duty cast iron chamber & wheels. Adult supervision for children under 16 recommended. (9"L x 3 1/2"w x 3 1/2"H, 2 1/4 lbs.) Single shot breech loading cannon. Ammunition storage is in rear of drag beam. Made of all cast iron, from the original 1929 tooling.