The VSS (Russian: Винтовка Снайперская Специальная, Vintovka Snayperskaya Spetsialnaya or "Special Sniper Rifle", GRAU designation 6P29), also called the Vintorez ("thread cutter"), is a suppressed sniper rifle that uses a heavy subsonic 9×39mm SP5 cartridge and armor-piercing SP6 cartridge. It was developed in the late 1980s by TsNIITochMash and manufactured by the Tula Arsenal. It is issued primarily to Spetsnaz units for undercover or clandestine operations, a role made evident by its ability to be stripped down for transport in a specially fitted briefcase.