Window Channel - which size?

[RAS]

Having refitted the rear window channel, it's lasted about a week, before disappearing into the base of the door again, so I guess its time to replace it.

Rather than strip the door to get the dimensions, I've tried to measure the aluminium channel in situ and I make the width just over half an inch. I've checked the Woolies site and they have two sizes with the right profile, 1 is 12mm (1/2") wide and the other is 16mm (5/8"). I'm leaning towards the 1/2", but don't want to order the wrong size.

If someone knows the correct size would appreciate the answer.

The links to the two products are below:

http://www.woolies-trim.co.uk/pc-1485-290-window-c...
http://www.woolies-trim.co.uk/pc-1487-290-window-c...

Many thanks
Roger

Edited by RAS on Sunday 4th May 16:48