In the age of ultra-lightweight everything, Sea To Summit have developed a range of ultra-lightweight dry sacks to save those crucial few grams. Using a 15 denier Sil/PU nylon fabric Sea To Summit call Ultra-Sil® Nano, a lightweight side release buckle and a thinner roll top closure we have created a dry sack that is 30% lighter than our standard 30 D Ultra-Sil®