Likewise, I'm also thinking of the Isabella air X-tension for our Eriba Troll 535. I wrote to Isabella a few weeks ago for advice about which tunnel to purchase. They wrote back to say buy the European VW California version NOT the family van version as this would fit both the caravan rail, or my Thule Omnistor awning rail. Same as UK VW California version but presume the zip out panel at front window end instead of the back? However, I have not managed to find one to buy yet. Leisureshop only selling UK version, although they say they will try and purchase the European version from Isabella.

It would be better to have a specific tunnel for the Eriba though, so I might hold out for that... if it ever materialises.

Only thing I don't like about the Isabella X-tension is lack of ventilation. One window to open no good if raining and hot or cooking inside etc

This thread is very helpful, thanks.

Anne

Just to provide some contrast - we have just finished three weeks away (two trips) using our brand new mk2 Pop Air Pro 340 on our Triton; and it is brilliant - quick and easy to put up and take down (though putting up is easier with two people, just for feeding into the rail) and really stylish when up - plus we have added the bedroom annexe and the porch extension (both excellent). We had two days with some rain and the first time it ran down the caravan wall (we have the rubber strip fitted to the rail, but this didn't prevent it), however I then added some blu-tak at the ends of the rail strip (thanks to whomever posted that on here) and that seemed to stop any further water ingress.
I would be worried about the tunnel bit of the Isabella X, where it connects to the Eriba rail, as it's on a downward slope from the awning and that must surely increase water load on the join? Do you get any problems with that?

The weather has been so hot that for both our trips with the new Air X Tension awning it hasn't rained a drop! The tunnel is the VW California one and fits fine - but yes, it does slope down to the caravan. However, I plan (when the rain does eventually come) to have the awning close enough to the caravan that there's a small sag in the tunnel roof so that water from either the caravan roof or the awning roof will both run into it - it has a light weight guy line at the top/middle of the tunnel which means you can pull this down to one side so any rain should pool in it and run off sideways. Presumably that's the same issue for the awning when connected to a VW van, as the awning is going to be higher on a VW as well.

Would be interested to know how this stands up to windy weather. Can you attach storm straps to hold down?

Just for info, we used our Isabella Air X tension in torrential rain over coronation weekend and we had no trouble with the tunnel pooling water - I pegged it out so that it slopes down and almost all the water had run off after the storm.

If you look at the pictures on page 1 you can see that it has eyelet loops at the corner but not full storm starp buckles. It does however cope well with wind and as its a drive away awning, in really bad wind you could even zip up the panel on the side attacehd to the caravan, so theres nowhere for wind to get in and try and lift the awning - not that we have needed it despite pretty windy weather. All in seems more secure in wind than our old metal frame awning

I would like to echo all Seadog has said.
We bought an Air X tension last summer and are very pleased with it. We modified the fit to the van by putting a cut in the kader strip so it lengthens the side of the tunnel where it fits our Troll for a better fit. We conveyed this information to Colin from Isabella along with photos as he was interested for their manufacture of a tunnel to specifically fit Eriba's. Having owned several awninings over the years, a vanderhorn, two lightweight nylon (self adapted to fit) a pop air 360 and a Unico I feel that we have at last something which suits our needs. A bonus too in that it will fit our VW camper should we not wish to tug the Troll.

How does the Isabella compare to the Pop Air Pro?