Troy's HK Front Folding BattleSight is easy to install and deploy, with no levers or springs to fumble with. No tools required for adjustment. Features- sight can be moved or taken off without permanent modification to the firearm, stainless-steel cross-locking system ensures sights remain upright and zeroed under extreme combat conditions and a push of a button folds the sights securely out of the way until you need them again. Requires front sight tool. Standard M16 A2 front sight.