This is the rail used for an authentic M4A1 block 2 straight rail build. The rails come in black or FDE. The FDE is at times hard to find. It is normally what is wanted for an authentic clone build of the Block 2 M4A1.
The Daniel Defense Rail Interface System (RIS II) was designed at the request of the United States Special Operations Command (SOCOM) for the SOPMOD II program. SOCOM had a specific requirement for a free float M203 solution and Daniel Defense responded, designing a revolutionary product to meet the government’s need. The Daniel Defense RIS II allows the individual operator to free float the M203 grenade launcher without additional parts. As important, special tools are not required to mount the M203 grenade launcher. This was accomplished by integrating all the needed parts to free float the M203 into the rail itself. The Daniel Defense RIS II is to be used in conjunction with the MK12 Low Profile Gas Block.
DD RIS rails for M4A1 Block 2 have been hard to find. Some years are easier than others. Sometimes you have trouble finding FDE, sometimes trouble finding black. One suggestion if you are questioning the black, and this is the rail available, rattle can it, or get FDE rail covers, like these: DD rail ladder covers for RIS rails in FDE made by Ergo
All Daniel Defense RIS rails sold by Charlie's include all hardware (screws, barrel nut and color matching RIS hex-ring). Installation wrench is not included, but offered for sale here: Daniel Defense RIS wrench, heavy duty