Product Description The TacFire MAR121P Firing Pin Retainer is a precision-crafted replacement and upgrade component designed to keep your AR-platform bolt assembly running reliably. Made from durable stainless steel, this retaining pin securely holds the firing pin in place within the bolt carrier and is compatible with both 5.56x45mm NATO and 9mm Luger bolt configurations. Whether you are performing a routine maintenance repair or completing a custom build, this drop-in retaining pin delivers dependable function and lasting corrosion resistance at an affordable price point. Product Highlights Compatible with both 5.56x45mm NATO and 9mm Luger AR-platform bolts for versatile use across multiple builds Manufactured from stainless steel for superior corrosion resistance and long-term durability Serves as a direct drop-in replacement, making installation straightforward with no modification required Extremely lightweight at approximately 0.01 lbs, contributing virtually no additional weight to your firearm Identified by MPN MAR121P for easy reordering and parts sourcing Specs Brand: TacFire Model: Firing Pin Retainer MPN: MAR121P UPC: 686294505737 Material: Stainless Steel Compatible Calibers: 9mm Luger, 5.56x45mm NATO Weight: 0.01 lbs Disclaimer: We strive to provide accurate and up-to-date product descriptions, specifications, and images; however, errors or omissions may occasionally occur. We are not responsible for any inaccuracies or discrepancies in the content provided. If you notice anything incorrect or unclear, please contact us so we can correct it. When in doubt, we recommend verifying details directly with the product&';s manufacturer.