I would invite you to do your homework before buying. I'm not saying don't, just that you need to know what you are in for as you use them.
The zippers on the existing GIVI bags are sh!t. The bags are NOT water-resistant for any kind of rain. A light rain gets your contents wet and if you forget about airing it out, things can get musty in there after only a few days (speaking from experience).
I would love to see the new ones with better zippers and more waterproofness (or at least better water-resistance).