Geissele 15" M-LOK MK14 DDC Super Modular Rail 05-575S is the longest option in Geissele's slim-diameter rail family - full-length coverage without the bulkier cross-section that comes with the MK16 or MK4 lines at this same length.

At 2.02" tall with a 1.27" inner diameter, the reduced grip circumference is where the MK14 really separates itself, and that difference becomes more noticeable the longer the rail gets - a 15" tube in a standard-diameter design starts feeling like a lot of handguard to wrap your support hand around, and this one doesn't. It's machined from 7000-series aluminum, mounting through the same 2.25" Geissele barrel nut used across the whole MK14 line, so alignment holds even after you've pulled it off a few times for maintenance.

M-LOK slots sit at 3, 6, and 9 o'clock, with a full-length Picatinny top rail for optics and iron sights. Weight comes in at 11.6 ounces bare, 13 with the barrel nut - reasonable for a rail this long, and lighter than you'd expect once you've handled the slimmer profile.

Key Features:

• 15" free-float length, full-length Picatinny top rail
• M-LOK slots at 3, 6, 9 o'clock
• 7000-series aluminum, Type III hardcoat anodized
• Proprietary 2.25" Geissele barrel nut
• Height 2.02", inner diameter 1.27", outer diameter 1.52"
• Weight: 11.6 oz bare, 13 oz w/ barrel nut
• Desert Dirt Color finish
• Fits mil-spec AR-15 upper receivers

For a full-length build in DDC that doesn't want the bulk of a standard-diameter rail, this Geissele MK14 rail is the pick.