Bought this recently for travel to hold a large charging device and cables. It's a bit smaller than I thought but was enough for a long weekend trip abroad. Tempted to now buy the larger one for road trips in my own country (UK) then use this medium one for camera batteries.
I already have and love a Pryke 31 backpack camera bundle so bought this to match. These are very good quality products, well designed compared to other camera back packs etc. Having said that I'm keeping mine for special trips where mud will not be involved!