Thanks. I've had a look round using that info. Found this:
But it says only for thermotop
Heater Telestart HTM T100 Remote Handset Kit | 1314637A
Webasto Telestart HTM T100 Remote Handset KitIncluded in the kit;Heater Remote control handsetControl unit with electrical wiring harnessComprehensive installation instruction manualPlease note; 12 volt onlySuitable for the following heaters; Thermo Top CThermo Top EThermo 90Thermo 90ST
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