The Slim Pro has every feature of the the Backpack Pro in a slightly lower volume and profile. If you’re below 5’10” and don’t need that extra space, this bag’s for you. It fits a 14in laptop, and the insulated neoprene sleeve fits a 32 oz water bottle (a narrow-necked bottle fits best), but it’ll also fit your smelly workout clothes or a wet umbrella (it was designed for a small bottle of wine). It all comes in materials that don’t get any more sustainable. The Slim Pro has the lowest carbon footprint of any professional backpack in its class.