Tannerite Exploding Rifle Targets are supplied as 2 separate stable compounds, that when mixed as indicated in the instructions, produce an audible explosion and a cloud of vapor when struck with a high velocity bullet. Pro Pack contains 20 1/2lb. tagets. FEATURES Comes as 2 separate stable compounds Produces an audible explosion and cloud of vapor For use with high velocity ammunition Contains 20 1/2lb. targets Note: this item is unavailable to be shipped to California