Call of Duty: Modern Warfare 3
It enables the player to equip two attachments on their weapon at once, similar to the perk Bling from Call of Duty: Modern Warfare 2 and Warlord from Call of Duty: Black Ops. Its icon is a "2", showing that it lets the player have two attachments on their weapon.
The player is able to combine the underbarrel attachments (Grenade Launcher, Masterkey Shotgun etc.) with any other non-underbarrel attachments except for the Hybrid Sight, as the toggle is bound to the same button.
- The Attachments Proficiency can be unlocked for the Model 1887, although it has no attachments. As such, the proficiency is grayed-out and unselectable for that weapon.
- When used with a weapon, the pickup icon will read "Custom" after the weapon's name, denoting that the weapon has 2 attachments.