Which year do you have? I think the late 2002 models onwards have the "floppy wiper" - which might have a different blade length/fitting - one of those Bosch Aero type.
See the fitting guide to see if you have one of the newer ones:
hi
go to b&q and buy an extending tape measure and you will be able to work out the length also look in your 2006 diary and it will give you imperial/metric conversions just in case you have the tape the wrong way round
les