When purchasing Brownells or any other brand from eGoods365.com store, you can be sure that (a) you are purchasing from US based company with the most responsive and friendly customer service; (b) an authentic, not a counterfeit and not a refurbished product.

M16 and M4 Rail Adapter Systems
The M4 and M5 Rail Assembly Systems are available to the public and come with the same quality rail systems that are provided to the US Government. They fit standard carbine and rifle gas length rifles that have the standard delta rings and handguard caps. The circle handguard cap is for the M4, while the triangle handguard cap is for the M16. You don't have to worry about damaging the aluminum handguards with the polymer rail covers that come with these rails, and your hands will be protected from the Picatinny rail. These adapter systems have drop-in installation, and you won't have to remove the delta ring or front sight. The installation process is simple and can be done just like a standard polymer handguard. To ensure that the Rail Assembly System is tightly secured, a retaining mechanism is included. With this mechanism, you can be confident that the laser aiming devices won't move, and you'll have zero retention.

These handguards are produced by a US Government contractor and are newly made. Brownells is proud to make these available to customers.