Complex sentence: The stock is a dual-voltage (1500 V DC & 20 kV AC) development of the DC-only E231 series suburban EMU design, and can run at speeds of up to 130 km/h in service.
Split into simpler sentences: The stock is a dual-voltage development of the DC-only E231 series suburban EMU design, and is capable of running off both direct current and alternating current. It can run at speeds of up to 130 km/h in service.