Size 18.5 " x 10" x 7", Total Capacity 1100 Cubic Inches/18 Liters,2 Liter Hydration, Weight 2 lbs. Included BPA free 70 ounce (2-Liter) hydration bladder - durable and puncture resistant Full main pocket with weather guard and reversed zipper, butterfly storage space to stash gear, front zip pocket with organizer and key clip, side mesh pouches to keep energy bars, water and sunscreen handy High density EVA foam with ventilation holes, mesh covering, and chest shock absorber add comfort and breathability to shoulder straps Built in safety-yellow rainfly with elastic edge to keep it in place