The Sea to Summit eVent Compression Dry Sack is a completely new concept in compression dry bags - there is no valve. This innovation uses an air-permeable base made of eVent waterproof fabric, which allows air to be pushed out of the sack, but won't allow water to get back in. Suitable to keep contents dry in any wet situation where the bag is not submerged. Features: Unique compression idea - allows air to be pushed out to compress, but water can't get in because of the waterproof, air permeable eVent fabric base Rugged 70 D nylon body & lid Waterproof seams - double stitched and tape sealed Roll top Hypalon; closure with lid and 4 straps evenly compresses and maintains compressed size Reinforced stitching on all stress points Pull handle on the bottom Super compact and very light Proper Use: Any roll-top dry sack must be closed properly to e