Durable Waterproof Material:Made of premium PVC tarpaulin with seamless voltage technology, this pannier bag is fully waterproof and built to withstand heavy rain while remaining lightweight at only 1.28 lbs (580g) Spacious & Organized Storage:Offers 426 cu in (7L) when folded and up to 610 cu in (10L) when expanded, with an interior compartment for classified storage of essentials Secure Roll-Top Closure:Roll the opening and fasten with side or top buckles for a tight seal. Comes with a detachable shoulder strap for convenient carrying. Reflective strap and brand logo ensure safer night riding Quick Release Mounting System:Features tool-free installation with a hook and 360° rotary buckle, making it easy to attach and remove from your bike’s rear rack Wide Rack Compatibility:Fits bike racks with tube diameters under 0.7 in (18mm). Includes gasket for racks under 0.43 in (11mm). Also compatible with some motorcycles. Reinforced fasteners adjust to rack widths between 2.8–5.9 in (7–15cm)