Topeak Wedge Drybag Medium (TT9818B)Topeak Wedge Drybag protects your gear while riding in wet conditions. The DryWedge pack is made from a tough, waterproof material, which is sonically welded and seam sealed to provide the ultimate protection in nasty weather. Roll closure keeps water and mud out and contents dry. Mounts to saddle rails and seat post with a nylon strap system.883466005976