The ČSD Class S 499.0 and S 499.1 are essentially locomotives with revised gearing for higher speeds and added electrodynamic braking system. They operate from the 25 kV 50 Hz overhead line electrification system in both the Czech Republic and Slovakia. Their design can be traced back to the locomotives produced by Škoda in 1962. S 499.0 had a maximum speed of 120 km/h (75 mph), with S 499.1 140 km/h (87 mph).