Reach the indicated level to unlock the item. 
Note: You must have sufficient grey tech to purchase the unlocked weapons.

Assault Pack: Level 16 
Auger (weapon): Level 18 
Bellock (weapon): Level 28 
Bullseye (weapon): Level 2 
Hawkeye Scope: Level 22 
High Density Ammo Chamber: Level 8 
Invisiblity (berserk): Level 4 
Kinetic Gloves: Level 6 
L23 Fareye (weapon): Level 12 
Mag-Propulsion Barrel: Level 26 
Marksmen (weapon): Level 1 
Prototype Ammo (berserk): Level 1 
Proximity Mines (berserk): Level 10 
Psychokinetic Helmet: Level 30 
Shock Suppressor: Level 14 
Snake Eyes (berserk): Level 12 
Voltaic Body Armor: Level 24