V Seven Weapon Systems is now offering Ultra-Light M-LOK Rail Sections. These rail sections are available in 3 or 5 slot lengths and are machined from 7075-T6 aluminum. The cross bar sections have been scalloped in the center and pockets of material have been machined out of the back to the rail to remove as much weight as possible.
The 3 slot rail section weighs 15.5 grams and the 5 slot weighs 21.5 grams. Those weights include the screws and M-LOK nut.