Pack compatibility:
These pockets are not compatible with the Superior Frameless Packs, the 70L packs or the 95L packs. 
These are only available for the 40L and 50L packs at the moment. 
These can not be placed above a tall side pocket. They must be on the opposite side of the pack if you add a tall pocket to your pack. 
 
This option will add an upper pocket to one or both sides of your backpack. The upper side pocket does not interfere with water bottles in the lower side pockets. 
 
It can be added to either the left, right or both sides of a pack. This is a great way to add bit of extra storage capacity to the outside of your pack, and is great for organizing small items such as a headlamp, extra snacks, etc. 
 
This option will add about 1oz to overall pack weight per pocket.
 
The elastic top closure option will be made out of the same fabric/color as the lower pockets on the pack.
 
The zippered option will be made out of the same fabric/color as the lower pockets on the pack. 
 
The Venom Mesh option comes with an elastic top closure.