Bastion high-quality custom magazine base plates for Smith & Wesson M&P Pistols. Full sizes chambered in 9mm, 40S&W, and 45 AUTO. SHIELDS chambered in 9mm and 40S&W. Replaces the plastic factory part. Personalize your firearm with a hard-coat anodized 6061-T6 aluminum plate laser engraved with the design of your choice.