2nd class Large blue Machin security definitive business sheet 20178.
This is a 2nd class Large letter Business Sheet stamp, coded M17L, printed 25/04/18 and first available in September 2018.
In this printing the MBIL code is to the right of the ND, as last year.
SG U3031 (ex U2969) (also used for other years)
NO HEADERS AVAILABLE - SORRY.