The Gage Weapon Pack #01 Add-on for PAYDAY 2 has 10 achievements.
While wearing the "Jean-Claude" mask, kill 100 enemies using only the Kobus 90 submachine gun.
While wearing the "Arnold" mask, kill 100 enemies using only the UAR rifle.
While wearing the "Dolph" mask, kill 100 enemies using only the AK5 rifle.
Kill 100 enemies using only the SpecOps submachine gun.
Kill 100 enemies using only the Signature .40 pistol.
While wearing the "Chuck" mask, kill 100 enemies using only the Crosskill pistol.
Kill 100 enemies using only the Eagle Heavy rifle.
Fill up 72 weapon slots.
Throw 100 grenades.
Buy the grenade case asset 100 times.