The MK5-R Rail System was designed to be used with Riflespeed adjustable gas block for on-the-fly adjustments for any length gas system.
 
Hardcoat anodized black
M-LOK modular mounting system
Full length 1913 picatinny top rail
Lightweight yet rigid design
Anti rotation tabs
Proprietary barrel nut interlock system locks up solid for mounting IR devices
Internal diameter: 1.25"
Fits forged and billet upper receivers
Integrated QD ports
Vented to reduce heat buildup during rapid fire
Window ports for Riflespeed gas block adjustments
 
Compatible Gas System Lengths:
Pistol
Carbine
Mid
 
Available Lengths:
6.9"
8.8"
10.3"
12"
13.5"
15"
 
*Uses a 30mm barrel nut wrench (not included), minimum torque: 38 ft lbs