Velo Transit Women's Quintessential 30 Waterproof Bicycle Commuter Backpack Waterproof bicycle commuter backpack Radio-Frequency welded liner creates 100% waterproof backpack Men's and Women's sizes available for exact fit Our new "Slick" Roll-top is easy to access and close, but still waterproof under extreme conditions. Comfort and stability are enhanced with the new highly contoured back panel and ergonomic shoulder pads.