Improved Iron Sights are an attachment featured in Battlefield Hardline. They can be equipped in the Optics slot on any handgun besides the .38 Snub and the MAC-10. They can be bought after achieving 30 kills with each specific weapon, or bought with a Voucher.
On some weapons, such as the 92FS, 45T, and G17, Improved Iron Sights replace the default iron sights of a handgun. The rear sight has a vertical green line, which is aligned with the front sight's glowing green dot. This attachment can make for a sight picture which is uncluttered and easy to line up on a target, and can also be clearly seen in the dark.
On many other handguns, such as the P226, .44 Magnum, and .40 Pro, rather than replacing the default sights, they add luminescent tritium dots inside the iron sights, with green or green-and-red colors. This makes it easier to acquire a sight picture in the dark, around smoke, or in other situations.
On the .357 RS, using this attachment will bring the iron sights closer to the player's view, making them seem larger and more defined. On the TEC-9, it has the opposite effect. No other sidearms are affected in this way.