81-740/741 (Rusich, Russian: Русич), is a type of rolling stock specially designed for running under the harsh winter climate of outdoor Moscow. Rusich also features a corridor connection, allowing passenger access between two contiguous cars. They are currently assigned to the metro lines including Arbatsko-Pokrovskaya Line, Filyovskaya Line, Koltsevaya Line and Butovskaya Line of Moscow Metro, and all lines of the Sofia Metro in Bulgaria. Automatic control system and universal control panel was designed by Tikhomirov Scientific Research Institute of Instrument Design (NIIP).