MW4 unlocks and attachments

Player level: 4 · Maximum weapon level: 72

Compatible slot types: Optic, Muzzle, Barrel, Underbarrel, Magazine, Rear Grip, Stock, Laser, Ammunition

Apex: Han X20 Skybreaker. Unlock at maximum weapon level; equipped separately from the five standard attachment slots.

Slots blocked by Apex: Optic, Stock, Barrel