Built from blued steel with ProMag®’s proprietary anti-fatigue chrome silicon springs and impact-resistant polymer baseplate, the ProMag Bersa® Thunder 9mm 17-Round Steel Magazine is an affordable aftermarket extended magazine, designed to deliver unparalleled reliability at a low, budget-friendly price. Often underrated and underestimated, Bersa’s PPK-inspired Thunder and .380 ACP pistols are a favorite among experienced shooters and frequent concealed carriers. Bersa’s pistols combine sufficient firepower with rock-solid performance at a price that’s hard to beat. Engineered to meet or exceed factory specifications for optimum fit and function in Bersa Thunder 9mm pistols, these ProMag magazines can endure serious operational abuse without sacrificing reliability. Backed by ProMag's legendary lifetime warranty. Made in USA.