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.
You can also grab the REI Sprig 12 Kids Hydration Pack for just $18.73 when you use promo code REIGARAGE at checkout. This pack comfortably fits kids ages 5-8. Choose from Jungle Spruce or Maiden Pink.
If you wish to purchase more than one pack, I would do them in separate orders. The additional 20% off that the promo code provides is only valid on one item per order.
Be sure to select in-store pick up to avoid any additional shipping fees. Otherwise orders of $50 or more will ship free.