`- Fastens to saddle rail and seat post \n-Additional access to main body (5L compartment) via zipper on the drive side\n- May be rolled up to adjust volume\n- Mesh pocket with the zipper on non-drive side \n- PU coated splash resistant 600 denier Nylon \n- Water resistant polyurethane coating on all zippers \n- Fits 25.4 - 34.9mm seatposts