> Can someone tell from the photo what size blind panels i need
> http://www.flickr.com/photos/cray5656/376766455/sizes/l/
>
> thanks

You should measure the gap.

If it's ~ 5 mm a 1 HP blind panel is needed.
If it's ~ 7.5 mm a 1.5 HP blind panel is needed.
If it's ~ 10 mm a 2 HP blind panel is needed.

Best wishes
Dieter Doepfer