Rapid deployment, thin, agile, and precise. This is the MCX Rattler. Featuring a 5.5" PDW barrel, the MCX platform has never been more compact or accessible. Ready to go where-ever it's needed. This upper receiver was designed from the ground up to be as discrete as possible while retaining all the capabilities of the MCX. Free-floating M-LOK handguards matched with a PDW upper, the MCX Rattler upper receiver is the ideal choice for fast-moving operators.