Exped Drybags. Lightweight nylon bags with taped seams, that the makers claim to be 100% dry. Very simple to use – fold over the bag top to close it (four times is a reasonable minimum if you really want to keep kit dry) and secure the seal by doing up the quick release clip. These are not bombproof. Consider careful packing, and maybe padding, if contents are very sensitive. No container is waterproof if it has a hole in it! Sizes: XS (3 litres), S (5 litres), M (8 litres), L (13 litres). Sizes approximate – more folds mean less capacity. Buy a size up, if in doubt. Larger sizes (up to rucksack liner) available on request.