We actually use it to transport additional water supplies. Thats because the 10-l Ortlieb water sack fits inside perfectly. But of course、 you can use it for all sorts of other things … The bag has an all-round zip and is attached by means of two straps that are inserted through the eyelets on the lid of the ZEGA PRO-case. The straps are secured with two plastic buckles、 and the length can be adjusted to suit the amount of water in the water sack. Approx. 12 l capacity - reinforced seams - non-slip base. Also suitable for the BMW R 1200 GS Adventure case.