This is (2) 25-pound bags of #4 Magnum Lead Shot/ Bird Shot. It measures .013" diameter per ball. Our graphite-coated, high-antimony Magnum Lead Shot (American Standard) has the equivalent hardness factor of 5% Antimonial Lead Alloy. Brand-Our vendor sources may vary according to availability and lead market pricing. Our manufacturers include Mayco/Lawrence, Winchester, Remington, and Eagle of Peru, RotoMetals and Hot Shot. Please email or call our customer service department if you have any questions on current stock or would like to request a certain brand