Daniel Defense RIS II M4A1 FSP Assembly – Free-Float Rail System

The Daniel Defense RIS II M4A1 FSP Assembly is a mil-spec free-float rail system designed for carbine-length gas systems with a front sight post. Originally developed for USSOCOM, this quad-rail handguard provides a stable mounting platform for lights, lasers, and vertical grips while maintaining consistent point-of-impact. The continuous top rail allows co-witnessing with fixed iron sights and maintains zero when accessories are removed and reinstalled.

CNC-machined from 6061-T6 aluminum with a Type III hard-coat anodized finish in black. Includes barrel nut, hardware, and installation wrench. Compatible with AR-15/M4 carbines with front sight posts and carbine-length gas systems. Does not require proprietary tools for installation beyond standard armorer's tools.

• Type: Free-float quad rail
• Compatible Firearms: AR-15/M4 carbine with front sight post, carbine-length gas system
• Material: 6061-T6 aluminum, Type III hard-coat anodized
• Rail Spec: MIL-STD-1913 Picatinny (four sides)
• Includes: Rail assembly, barrel nut, mounting hardware, installation wrench
• Use: Accessory mounting, enhanced weapon modularity