Granite Gear eVent Sil Compression Drysacks Waterproof Stuff Sack Waterproof and ultralight As the sack is compressed air is forced out the eVent bottom See-thru Sil-Nylon fabric allows you to see what's inside. New Lineloc technology is 30% lighter than webbing compression systems 10L: 2.8oz 5 x 7.25 x 20"; 13L: 2.9oz 5.25 x 7.75 x 21"; 18L: 3.4oz 6 x 8.75 x 22.5"; 25L: 3.8oz 7 x 10 x 25"