12.7mm VSSK "Vychlop" silenced sniper rifle is one of the most recent creations of famous Russian Instrument Design Bureau (KBP). This rifle is said to be in use only by special elements of FSB and MVD, which conduct anti-terror and high importance anti-crime operation. It must be noted that rifle is known under two alternate designations, VKS or VSSK, the former appearing to be more official. The codename "Vychlop" (Exhaust) comes from the development program.

12.7mm "Vychlop" silenced sniper rifle is developed for special operations that require silent firing and penetration much superior to that provided by 9mm VSS silenced sniper rifle. Typical targets for VKS / VSSK Vychlop rifle are cars, terrorists in heavy body armor or behind covers like car bodies or other thick covers.

Accuracy is claimed as 1 MOA (Minute of Angle) at 100 meters range with precision bullets, and maximum effective range is given at 600 meters.