AR-15 17" Free Float M-LOK Handguard Specification:

• Ultra Slim Design for Comfort and Weight Reduction.
• Cut for weight reduction, this system still retains the utmost in robust construction and provides a Picatinny top rail mounting system and plenty of attachment points for all your M-Lok accessories.
• Works with low profile gas blocks.
  
• 7 Sides of M-Lok Slots Around The Body.
• M-Lok & Picatinny Rails Hold All Your Accessories.
  
• With Anti-rotational Tabs For Secure Fit.
• 1913 Rail Meticulously Engineered To Be Ultra Light.
• Steel Barrel Nut And Allen Wrench Included.

Guide Type: M-LOK Handguard
Compatible With: AR-15
Material: 6061 Aluminum, Steel(Barrel Nut)
Total weight (including Barrel Nut): 390g
Barrel Nut: External diameter: 1.35 inch, Inner diameter: 1 inch
Barrel Nut Thread Size: American Thread 1 1/4-18 UNC
Wrench Size: 1 1/4" Crowsfoot Nut Wrench
Rail Type: Picatinny Weaver.
No. of Rails: 1.