In STALKER: Clear Sky, flash drives provide access to unique upgrades to weapons and body armor. To open all the improvements available in the game, each of the technicians must be given three flash drives with technical information. You can find the data you need in the most unexpected places.
The flash drives in "STALKER: Clear Sky" are a kind of prototype of the sets of tools from "Call of Pripyat". But you can get them either as a reward for a quest, or with the appropriate data. Each technician, having the necessary information, can open three upgrades.
Flash drives for a technician from the "Clear Sky" group
A flash drive with an upgrade of lightweight body armor can be obtained as a reward for completing the first quest from the commander of "Clear Sky" at the location "Swamps". The other two flash drives contain information about submachine gun modifications. One is a reward for completing the "Superiority" quest, information about the other will be given by NPC "Nimble" for 800 RU.
Information for the Cordon Technician
The first flash drive on Cordon opens up access to a very important upgrade for automatic weapons. You can find the drive by searching the corpse of the military stalker "General" after clearing out the enemy ATP. The information on the two remaining flash drives concerns the modernization of shotguns. On a tip from the stalker "Tramp", you can get data on stabilization systems for pump-action shotguns, and the trader "Shilov" for 1000 RU will indicate the location of the drive with unique information about the reloading mechanisms.
Flash drives for the Transparent technician
The Bandit Technician can make very useful armor upgrades. To obtain an additional PSI protection system, you need to contact one of the three NPCs for a tip: the stalker "Vasyan", the bartender "Borov" or the trader "Zubu". The same NPCs will give information about the flash drive with data on the systems of the closed breathing cycle. In both cases, the cost of the tip will be 1500 RU. The third flash drive can be found in the basement of the destroyed "Flea Market" after the plot incident with the attack of bandits on the main character.
Information about improvements for Uncle Yar
Technician "Svoboda" performs unique modifications of sniper rifles. Information about two flash drives can be given by the bartender "Ganzha" or the trader "Ashot" for 2000 RU. To obtain another carrier, you will need to complete the quest to eliminate a group of mercenaries.
Flash drives for neutral technicians from Research Institute Agroprom
The already mentioned trader "Tooth", the bartender "Borov" and the neutral "Vasyan" can sell information about two flash drives for a technician at the location of Research Institute Agroprom for 500 RU. The media contains data for the modernization of the barrel and muzzle brake of pistols. Another flash drive can be found on a paid tip from the commander of the "Duty" Krylov.
Information for a technician from the "Debt" group
Gromov makes improvements to LMGs. Information about the first USB flash drive can be purchased from the Mityaya merchant for 5000 RU. The second flash drive will be a reward for completing the quest to find a loser stalker PDA. Data on the last drive can be redeemed for 4000 RU from Major Zvyagintsev.