You'll love the CamelBak Arete 18 Hydration Backpack if you're the type of minimalist hiker who calculates your gear's weight in grams and cuts off all excess weight in the form of tags and unused straps. Tipping the scales at a mere 11 ounces, this slim hydration pack caters to your ultra light hiking obsessions. A 1. 5 liter 50 ounce hydration reservoir keeps you pleasantly hydrated during multi hour trips and shorter day hikes. Plus, you'll find a built in security pocket for stashing away trail snacks and smaller items such as cash and keys. Capable of serving double duty, the Arete quickly converts into a dedicated reservoir sleeve for use in a larger pack. Suddenly, everyday packs are equipped to hold 1. 5 liters of water without worrying about it leaking out or jostling around your pack. Additionally, Air Mesh shoulder straps provide a supportive fit that reduces perspiration build up in sweltering summer weather.