The B5 Systems B5 SRK-1660 SRK EXTENTION KIT BLK combines precision engineering with practical versatility, delivering a Sierra K Extension Kit designed for AR-15 platforms in a durable black finish. This extension kit enhances modularity and customization for shooters seeking a streamlined balance between control and comfort, enabling a more versatile cheek weld and improved overall length for varied shooting scenarios. Built by B5 Systems, the kit integrates seamlessly with compatible AR-15 receivers to provide a reliable, stable platform that supports enhanced stock alignment, quicker target acquisition, and consistent repeatable indexing during rapid fire or precision work. The black anodized construction offers abrasion resistance and a clean, low-profile appearance that complements other rifle components while maintaining durable performance in field or range environments. Ideal for sport shooters, hunters, and tactical enthusiasts, the SRK EXTENTION KIT BLK is designed to expand your options without sacrificing aesthetics or function, empowering you to tailor your setup for extended range sessions, dynamic field use, or precision drills with confidence and ease.