CamelBak updated its tried and true Classic Hydration Pack with a host of new features to ensure that you get the hydration you need when you hit the road or the trail. The minimalist design still leaves some room at the front pocket for one or two trail essentials, e. g. your phone, granola, or a wallet. At 6. 7 ounces, the Classic truly suits the minimalist biker or hiker who is attempting to cut any unnecessary weight during intense activity. An Air Mesh back panel and lightweight mesh harness allow your torso to breathe under strenuous exercise, reducing the accumulation of sweat. The pack's body features a nylon and diamond Clarus construction treated with DWR and PU for a sleek, water resistant finish. Because of its reflectivity, you can safety take the Classic out with you for a ride after dark. Season after season, CamelBak's super scientists have been hard at work refining and perfecting the Antidote reservoir, the industry's most popular solution to hydration. At the turn of a cap a quarter turn to be exact, you can open or close the reservoir, refilling and securing it again in seconds. Center baffling and a sleek design prevent your water from jostling about inside your pack while running, hiking, or hitting the park.