Head over to REI Garage (formerly REI Outlet) and grab the REI Tarn 18 Kids Hydration Pack for $20.73 when you use promo code REIGARGE at checkout. This pack comfortably fits kids ages 8-12 and has all the high quality features and materials as the REI adult packs. Choose from two different colors, Puget Sound (pictured above), or turquoise jungle.