The British Rail Class 508 (or 4PER) electric multiple unit (EMU) passenger trains were built by British Rail Engineering Limited, at Holgate Road carriage works, York, in 1979–80. They were the fourth variant of BR's standard 1972 design for suburban EMUs, eventually encompassing 755 vehicles and five classes (313/314/315/507/508). They have worked mostly on the Merseyrail network since 1983 and continue to do so, having been refurbished by Alstom's Eastleigh Works. The Class 508 unit is now 43 years old.