The Troy Industries Rear Folding BattleSight is the gold standard for back up iron sights. The folding sight locks securely into the vertical position with a solid stainless steel crossbar, yet folds easily with the push of a button. These standard sights feature a traditional dual aperture set-up that is perfect for shooters used to the standard M4 sight picture or those who want to take advantage of the battle proven speed of a round aperture. Bought new and mounted on one rifle. Rifle was sold and sight has been sitting in my parts box ever since. Perfect condition! These are around $140 after shipping and tax. Firm on $80 cash. Live in Justin and can meet anywhere within reason Sat. or Sun. Will not ship! Call or text 770-312-596one if interested!