Were do i get the upgrade kit part number 3455103 and how mutch is that.

flyingdutchman: Hello I have 3 beoline 6000 mk1 handsets: 1 x fw version 001-1.60 0103071019-2G4 2 x fw version 001-1.40 9912030929-2g4 I use them in the UK, the sets are from the US. I have seen fw version 2.x been mentioned in forums. A couple questions, it is worthwhile to get them upgraded and is it possible and needed to get them upgraded to a