Though it's sold separately, the Contrail Day pack is meant to complement Osprey's wheeled Contrail bag. This carry-on-sized 26-liter pack attaches to the Contrail's handle via a discreet flap sewn to the top of the bag. When not in use, the flap attaches to the bag via a set of sewn-in magnets, which keeps it out of the way. We liked the variety of mesh and padded pockets for organizing stuff, with compression pouches on each side for water bottles. There are cushioned slots for an iPad, as well as a laptop up to 17 inches. The only thing we struggled with were the closely-spaced padded shoulder straps, which chafed our neck and shoulders during one hike.
It’s also too bad the pack doesn’t open flat so you can run the laptop pouch through security on its own; Many new bags do this and it’s a win-win for both you and the TSA folks at the airport. Overall, we thought the pack made a great combination with the wheeled Contrail. For business travelers who like to get off the beaten path, it's a worthy accessory. ($129)