Precision Machined from Aircraft Grade Aluminum for Maximum Strength 20 Top Slots, 11 Left and Right Side Slots and 10 Bottom Slots Features Innovative Double Locking System with Zero-Gap Tight Tolerance for Most Secure Fit Great Zero Retention Capability for All Accessories Installed on the Rails Intensively Tested by Field Experts and Demonstrates Most Satisfactory Performance Friendly Installation, No Gunsmithing Required