They were the first member of the ORGANIZATION@1 family , which also includes Classes NUMBER@1 , NUMBER@2 , NUMBER@3 and NUMBER@4 , and is the most numerous type of ORGANIZATION@2 built in the post-privatisation period of LOCATION@1 's railways .

The Electrostar family also includes Classes NUMBER@1 , NUMBER@2 , NUMBER@3 and NUMBER@4 , and is the most numerous type of ORGANIZATION@2 built in the post-privatisation period of LOCATION@1 's railways .
