The BS-1 Tishina is a silenced Russian 30mm grenade launcher. It is developed specifically for the AKS-74U carbine. It uses a bolt-action mechanism to load blanks into the chamber along with the 30mm grenade. Pulling the trigger ignites the blank which in turn ignites the charge on the grenade causing the grenade to be expelled from the barrel. The "tishina" name comes because it is a silenced (Tishina means silence in Russian) grenade launcher.