Chrome, the mavens of commuting equipment, built the Saddle Bag Rolltop Pannier to keep your essentials protected during your commute. Chrome's unique knurled welded construction makes for an incredibly durable bag that's waterproof, without unnecessary bulk. And that helps to make this a true long term piece that just may outlast your next bike or three.This bag is constructed out of waterproof 600 denier nylon up top, with an abrasion resistant Hypalon base panel. The panels are bonded by a knurled welded construction, which uses high frequency radio waves to permanently bond the pieces of fabric. This is an essential step for creating a truly waterproof layer, and minimizing bulk. That should give you plenty of confidence for stashing your computer in the internal 15 laptop sleeve, regardless of what Mother Nature throws your way. This bag includes a rack adaptor that stays on the rack, making removing this pannier a piece of cake. And the burly tote straps make it easy to carry over your shoulder. This bag is rated for loads up to 55 pounds. The Chrome Saddle Bag Rolltop Pannier is available in a 20L size, and in the color Black.