Junkers automatic heater membrane.
This membrane has the letter E printed on the upper part of the metal plunger.
In any case, if your heater appears in the list of compatible models below, this membrane is the one for your heater.
It is possible that the old original membrane of your heater is yellow. Junkers has been changing all the yellow membranes for some time now for these much more resistant transparent silicone ones.
If your membrane is torn or deteriorated, your junkers heater may not turn on, spark or not heat enough.
7736501882 WRN 11 KI B
7736502104 WRN 11 KI B
7736501881 WRN 11 KI N
7701331706 WR 11-2 B 23
7701431623 WR 11-2 B 31
7701331705 WRD 11-2 B
7701431622 WRD 11-2 B 31
7701331704 WRD 11-2 G 23
7701431611 WRD 11-2 G 31
7701331692 WRD 11-2 KM E 23
7701431597 WRD 11-2 KM E 31
7701331801 WR11B23S3595
7701431711 WR11B31S3595 1795
WR11G23S3595 7701431702
WR11G31S3595
7701431589 WR 8 G 31
7701431556 WR 8 P 31
7701431592 WR 8 P 31