The Leapers UTG MNT-754 Model 4 Detachable Front Sight for Handguards is Designed to Use with AR Handguard Rails Quad rails or High Profile Gas Block. comes complete with A2 Square Post Sight Assembly to Fit all Picatinny/Weaver-style Rails. Quick Detachable Low Profile Front Sight Tower With Thumb Nut with Locking Retention. Precision Elevation Adjustments to Enhance Shooting Accuracy. UTG Limited lifetime warranty.