A0041594903 Spark plugs what are they for?

[bdabdabeav]

Clearing out some parts and found 20 of these plugs new and boxed. They're ngk r plugs, iv had a quick look through EPC but couldn't find which engine they'd fit seem to remember 272 or 156 but unsure, any help?

 

[grober]

ACCORDING TO THIS 004 159 49 03-004 159 49 03-004 159 49 03 - 1282-MERCEDES - 1231-NGK - Spark plug cross reference
They are the equivalent to PLKR7A platinum plugs


http://www.midlandvehiclecomponents...ical Bulletins/NGK/2008/spark_plug_plkr7a.pdf