What is a hydration-ready sleeve?
Hydration-ready does not mean the pack comes with the reservoir but that it can be added to it. It is a pocket of fabric, usually up inside and against the back panel of the pack that the hydration reservoir is put into. There is also an exit, allowing the drink tubes to be routed to the shoulder strap, as well as guides or clips on the shoulder strap for the tube. Starting with packs made in 2004, all JanSport Tech packs that are hydration ready also have the toggle needed to hang the new JanSport/Nalgene reservoirs.