An attachment which lengthens the barrel, increasing muzzle velocity.
― In-game description
The Flash drive with data on submachine gun barrel modification is a mission item in S.T.A.L.K.E.R.: Clear Sky.
General information[]
The flash drive contains upgrade data for a Viper 5 and can be delivered to Gray in the Clear Sky base at the Great Swamps for a reward of 1125 RU, after which he will be able to apply the upgrade to the player's weapons.
Location[]
The flash drive is given to the player by Docent Suslov, Clear Sky's trader, as a reward for completing the mission Reinforce Clear Sky's presence in the Swamps.
