How to Unlock the Slimline Pro Optic in Modern Warfare 2

The Gunsmith is one of the defining features of Call of Duty: Modern Warfare 2, allowing players to completely customize their weapons to their liking. This year, weapons belong to different platforms, and weapons within the same family share attachments with one another. Some attachments, however, like the Slimline Pro optic for the M4 weapon platform, are seemingly impossible to unlock at the moment. This sight in particular is a favorite from Modern Warfare 2’s campaign, so people are desperate to unlock it for their M4 loadouts. Here’s how to get the Slimline Pro optic in Modern Warfare 2.

How to Get the Slimline Pro in Modern Warfare 2

The Slimline Pro optic is a sight for the M4 weapon platform in Modern Warfare 2 multiplayer, so it can be used with the M4 assault rifle and other weapons in the same family tree like the M16. As a matter of fact, unlocking all of the optics for the M4 actually requires you to max out every gun including on the weapon platform. Even after doing so, however, the Slimline Pro optic and a few other attachments will still remain locked. So, what gives?

At the moment, the Slimline Pro optic is seemingly unobtainable in Modern Warfare 2 multiplayer. The only way to use the attachment in your custom classes is to play a private match. There’s no way to use it in standard multiplayer matches at the time of writing.

There are a handful of attachments in the same situation as the Slimline Pro, with no unlock criteria listed at all. Usually, the game will tell you which weapon you need to level up to unlock the desired attachment. The Slimline Pro doesn’t say anything at all when you hover over it in the loadout menu. Hopefully, Infinity Ward addresses this with a patch soon.

There’s also a possibility that these attachments will be unlocked by leveling up weapons coming with the launch of Modern Warfare 2 Season 1, which is currently slated for November 16. The new Warzone 2.0 and DMZ modes will be released at the launch of Season 1 as well, so there’s a lot for Modern Warfare 2 players to look forward to. In the meantime, there are plenty of attachments to unlock, weapons to level up, and camos to grind for.

Call of Duty: Modern Warfare 2 is available now on PC, PS4, PS5, Xbox One, and Xbox Series X|S.