The Colt OEM Series offers a no-compromise solution for consumers and dealers to build and offer customized rifles based on the proven Colt M4 Platform. Handguards, Buttstock, Trigger Guard, Magazine, and Rear Sight have been omitted completely. The OEM2 is build with a Low Profile Gas Block and without Handguard Retaining Ring to allow for the use of most aftermarket free float handguards.