One of the toughest and most effective rail systems for AR-pattern rifles available on the market to date. Utilizing their patented Bolt-Up barrel nut system designed at the behest of the United States Special Operations Command for the SOCOM II program, the MK18 rail features an incredibly rigid two-piece design optimized for use with the standard M203 grenade launcher when the lower section is removed. Incredibly rigid when installed yet weighing in at just 17.7 Oz, the RIS II M4A1 free float quad rail is the perfect option for clone-correct builds or anyone looking for the toughest rail on the market.

Features:

• Uninterrupted top rail
• Designed for and adopted by USSOCOM
• Quad rail design includes rail covers
• Configurable sling swivel attachment points
• Combat proven Bolt-Up mounting system
• Grade 8 military specification fasteners
• Aircraft grade 6061-T6 aluminum
• Type III hardcoat anodized finish
• Steel barrel nut
• Anti-rotation tabs
• Free float
• Length: 9.55"
• Width: 2.23"
• Height: 2.25"
• Inside diameter: 1.15"
• Weight: 14.1 oz
• Made in the U.S.A.