ProMag magazines are designed utilizing both traditional stamping and welding of heat-treated high carbon steel, and modern precision injection molding of mil-spec polymer compounds. Every ProMag magazine is backed by a lifetime guarantee against manufacturers defects. Made in USAFeatures :50-round drum magazineFits Sig Sauer Sig Pro 9mm pistolMagazine body constructed of a proprietary DuPont Zytel based polymerBlue steel upper magazine towerInjection molded magazine followerMagazine spring formed from heat treated stainless steelMade in USAMagazine Restrictions: The following states have magazine restrictions. Your order will not ship to those states if in violation of these laws and will be subject to cancellation and a 15% restocking fee. California - Limited to 10-round capacity. Connecticut - Limited to 10-round capacity. Colorado - Limited to a 15-round capacity. Delaware - Limited to 17-round capacity. Hawaii - Handguns limited to 10-round capacity Illinois (Cook Co, Aurora, Highland Park) - Pistol mags are limited to 10 rounds. Massachusetts - Limited to 10-round capacity. Maryland - Limited to 10-round capacity. New Jersey - Limited to 10-round capacity. New York - Limited to 10-round capacity. Road Island - Limited to 10-round capacity. Vermont - Handguns limited to 15-round capacity, Rifles limited to 10-round capacity. Washington DC - Limited to 10-round capacity. Washington - Limited to 10-round capacity.