The Daniel Defense M4A1 FSP RIS II is a SOCOM/SOPMOD II–spec rail interface designed for the AR-platform, built to support modern mission equipment while maintaining the intended sighting and grenade-launcher compatibility. It features the RIS II design approach requested for SOPMOD II, including interface geometry that supports the M203 grenade launcher setup and a top-rail cutout for a standard front sight base on a carbine-length gas system.

Key features

• Constructed from 6061-T6 aluminum with a Black finish
• RIS II architecture designed for SOPMOD II / SOCOM requirements
• Top rail cutout accommodates a standard front sight base on a carbine-length gas system
• Engineered to support free-float operation for the M203 grenade launcher without additional parts

If you’re building out a Daniel Defense–style M4A1 FSP configuration, the RIS II provides the rail interface geometry and material foundation needed for a reliable, mission-focused setup.