The SnaPack Tarp is essentially a squidgy box with shoulder straps and very little else. It is uncompromisingly designed to do one thing – carry your climbing gear short-ish distances to the bottom of the crag and then help you find the gear you need, as you do routes and move along the cliff for further climbs. It comes with a basic rope tarp to help keep your rope clean once out of the pack. It is not a pack designed for climbing with, let alone mountaineering when you will need ice tools and crampons. It is designed with one specific task in mind that it does well, but not to be versatile. It is though relatively cheap, making up to certain extent for the lack of versatility.
The double-style zips make packing and un-packing the bag a breeze, and because they run the whole way down the length of the pack, there is no more of the traditional rucksack experience of something small like a nutkey or belay plate invariably getting lost at the very bottom of the pack under all your other kit. The shoulder straps are also cleverly designed to work like handles on a basket, so even if you don't fully zip up the bag, you can carry it basket-style along to the base of the next route with out much fear of things falling out. The material is the reinforced rubbery tarp material like on the many duffle bags that all copy the original North Face ones and seems hardwearing after nearly a year of regular use. I have managed to bust one of the stiffened corners a bit, but it doesn't look like the actual seam is likely to break.
So the SnaPack Tarp does what it is meant to very well but won't do much else. Nevertheless I started realising some years ago that “a general purpose pack”, whilst the optimal solution when a skint student, actually wasn't quite perfect at anything.
So if you already have a lightweight mountain sack that you don't want to wear out dragging along the bottom of Stanage, or the top of Pembroke, then something like the SnaPack is well worth considering.
Currently it only seems to be available online from Urban Rock (although I bought mine from V12 last summer)