The Altura Vortex 2 Waterproof Compact Seatpack is ideal for bike packing &commuting. Fitting around the seatpost the Vortex is lightweight & fully waterproof &provides adjustability to fit a range of seat positions and post sizes. The Altura Vortex Waterproof Compact Seatpack boasts an IPX 6 rating because of its welded seam construction and Hyperlon reinforced areas making the Vortex protected against heavy rains, but not submersible and perfect for bike packing and commuting. The Vortex uses a simple hook and loop mounting system with  featuring reflective details to help improve visibility   Altura Vortex 2 Waterproof Compact Seatpack Features Fully waterproof to level IPX6 Lightweight Welded seam construction Roll top closure for adjustable volume Hook & loop wrap mounting system Hyperlon & Hook mounting system Hyperlon reinforced areas Kross side release buckles Structured inner support Reflective detail