Maxim’s RDB system is designed to convert your straight blowback AR-9 into a highly efficient and reliable roller-delayed system, providing unparalleled performance and accuracy. The CQB Length RDB system works with Maxim Defense CQB Length Buffer Tubes Only, ensuring a seamless fit and maximum performance. Maxim’s system is designed to provide a more efficient and reliable operation, reducing recoil and increasing accuracy. The roller-delayed system allows for a smoother cycling action, providing consistent and reliable performance. In addition, the RDB system offers several key features that make it stand out from other systems on the market. The roller-delayed system uses a locking mechanism that delays the opening of the bolt until the pressure in the chamber has dropped. This feature helps reduce felt recoil and improve accuracy, and making it easier to suppress. Overall, the Roller Delayed blowback system is a game-changer for anyone considering upgrading their AR-9. Its easy to install, reliable, and provides unmatched performance and accuracy.