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

Air Fuel Grenades: Level 12 
Assault Pack: Level 16 
Bio-amp Scope: Level 22 
Bioplasm Tracking Tech: Level 14 
Chloroform (berserk): Level 4 
HE .44 Magnum (weapon): Level 18 
High Density Bioplasm Chamber: Level 8 
Kinetic Gloves: Level 6 
Leech Barrel: Level 26 
M5A2 Carbine (weapon): Level 2 
Phoenix (weapon): Level 1 
Phoenix Ash (berserk): Level 12 
Psychokinetic Helmet: Level 30 
Ring of Life (berserk): Level 1 
Rossmore 238 (weapon): Level 10 
V7 Splicer (weapon): Level 28 
Voltaic Body Armor: Level 24