Rotopax 1 gallon gasoline pack is popular choice among adventure and dual sport riders. It is relatively cheap, very tough, requires minimal modifications on the bike (only luggage rack or pannier racks) and it can be completely removed from the bike in minute or two. Also, it can be used on any bike you have.
Capacity is limited, but it provides additional 70-90 km's for bikes like 690 Enduro. That is not very much, but it can save you from spending night in cold mountain forest.
Rotopax can is mounted to the bike (or any other vehicle) using Rotopax Pack mount and variations - DLX Pack mount or LOX Pack mount. Once mount is fixed on the bike, it is matter of seconds to mount Rotopax can onto it. Video explains all.
Perun moto Luggage rack SD is made to accommodate 1 gallon Rotopax can. Holes for Rotopax mount are pre-drilled on the rack. Here is how Rotopax Pack mount looks on the rack.
Pack mount can be bolted to the rack by inserting bolts and washers from below the rack. That would require too loose the bolts holding the rack on the bike, so rack could be lifted 2-3 cm.
Or, Rotopax Pack mount mod can be performed.
Either way, use large M8 washers under the rack and properly tighten up bolts (or nuts if Rotopax Pack mount mod is performed - as shown in picture).
When Pack mount is bolted to the rack, mounting and dismounting of Rotopax can is matter of seconds.
There are few more things to know.
Perun moto Luggage rack SD is powder coated. High quality coating process is used. But when dirt or dust enter between rack and Rotopax can, vibrations can cause paint to rub off a bit. This would happen even on anodized rack. It could be avoided by using self adhesive protective films on the rack, but I doubt that is necessary.
Rotopax 1 gallon gasoline pack proved its worth. It is really tough piece of equipment. Regardless of that, I always mount it so can opening is on the opposite side from the exhaust. Just in case I don't close it properly.
Next, because of the mounting points, all racks for 690 have similar issues and share weak points. Since mounting points are in front of loading surface of the rack, leverage can make some problems. Weight itself is not such a big issue, bouncing is. Actually, it all depends on where and how bike will be ridden (rode?). If full Rotopax is mounted onto the rack, fast and hard riding over bumpy terrain will put the rack to a test. Down-up forces could become too much to handle, for any rack.
Here is over simplistic animation of upper piece of my old rack - here is shown where are critical spots during the bouncing. Note that Perun moto Luggage rack SD is improved over previous version in many ways, leading to more than 100% stronger rack. Still, nothing is unbreakable. Keep in mind that it would not be good idea to make unbreakable rack, because forces won't be eliminated, they would just be transferred to threaded inserts holding the rack on the bike.
Using one strap that will go under the fender and above the Rotopax will significantly reduce bouncing and chance of rack failure. This may be needed only in extreme circumstances (full Rotopax, settings on hard, rally style riding, rough terrain...).
These are just words of precaution, and feel free to use Perun moto Luggage rack SD with 1 gallon Rotopax can, as it is intended for that.