Tpms again!

[plimagt3]

I have an A6 (C6-USA model) 2008 with TPMS. I've bought a set of Audi wheels (original equipment) for winter tires and now face the task of finding the correct TPMS sensors for them. I find equal numbers of posts for the Beru RDE 001 (433 MHz I think) and RDE 004 (315 MHz I think?). Does anyone know (a) which is correct, and/or (b) a reliable way to find out? Thanks!

[Kevin1]

I installed the Berus in the summer wheels for my 05 4.2 and they function fine.

[plimagt3]

FYI, the Audi options tag (found on my A6 in the spare tire compartment) shows among 44 3-letter/number entries 7K7 which translates to "Tire pressure control, frequency 433 MHzbasic level version" The correct Beru sensor is RDE007, part number 0 532 207 007