Forming the basis of southeastern's fleet, the Class 375 was built between 1999 and 2005.

 

Originally, the units were fitted with tightlock couplers, along with the slam-door stock in use by the same operator at the time. Later, these couplers were changed to the default couplers, as used on other Class 377.

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The units have a fair top speed of 100mph, and a varying number of seats, depending on the sub-class. Currently, all units are utilised by southeastern on services out of Charing Cross, Cannon Street, Victoria and on the Medway Valley line.

 

On 16 May 2015, unit 375301 returned to the Kent depot wearing a new livery, similar to the High Speed worn by Class 395.