Luftwaffe manufacturer SFW?

Hi all,

Could anybody help me in identifying the Luftwaffe manufacturer code SFW?

I have a (damaged) data plate from a Do17 which I believe to be from some part of the fuel injection system but I’m not sure. The plate contains the text “KRAFTSTOFFEINS….” But the rest has been torn off. I suspect it may have read Kraftstoffeinspritzung (fuel injection) but could be wrong. The HERST code is SFW with the NR being 21.

In the same batch I have a data plate for FL code 30560-3 which I believe to be something to do with the oxygen system as the part is called a “atemschlauch fur hohenatmer”, and a data plate for a footpump made by the Elektron co. m.b.H in Stuttgart. Has anybody any ideas on the parts locality in the aircraft of their use?

Any help would be much appreciated.

Darren