Link
Husqvarna
AA Class
Ahh, the 3.2 gallon petrol capacity of our beloved Terra/Strada 
Larger tanks? Not for me, like the lines of my Terra too much!
Enter, the Rotopax fuel pack!


BUT WAIT! There is a price to pay for installation
The hard nature of the plastic combined with the sharp edges of the words cast into the Rotopax combine to abrade anything they come in contact with
Solution? I went down to my local fabric/craft store, spent $0.99 on a sticky back foam pad.
Stick on the back of the pack, trim, and VIOLA! A cushion that also provides some additional flex when snugging down with the Pack Mount
There are also neoprene sheets that have a sticky back that are thicker, might provide additional cushion.
This brings me to the second piece of advice.
Check your pack if your temperature changes. I filled up in the heat, everything cooled down, and the mounting loosened up. Returned home along lots of rough dirt, found my handle bent because of the loose mount.

Larger tanks? Not for me, like the lines of my Terra too much!
Enter, the Rotopax fuel pack!



BUT WAIT! There is a price to pay for installation

The hard nature of the plastic combined with the sharp edges of the words cast into the Rotopax combine to abrade anything they come in contact with

Solution? I went down to my local fabric/craft store, spent $0.99 on a sticky back foam pad.
Stick on the back of the pack, trim, and VIOLA! A cushion that also provides some additional flex when snugging down with the Pack Mount

There are also neoprene sheets that have a sticky back that are thicker, might provide additional cushion.
This brings me to the second piece of advice.
Check your pack if your temperature changes. I filled up in the heat, everything cooled down, and the mounting loosened up. Returned home along lots of rough dirt, found my handle bent because of the loose mount.