Comes standard with a 2 L reservoir. Reservoir rides lower in the small of the back for better center of gravity. External shock cord for jacket or reservoir compression * Proprietary Passage PocketTM with left and right-handed access, which is fully accessible while wearing the pack. No worry dual magnetic closures * Ultra-lightweight, and first in the industry use of large hole mesh for increased breathability. Reflective details on the front and back for nighttime visibility * Stretch panels in the side with elastic mesh pockets for trash. Two lightweight mesh pockets in the front to carry bottles or food. Sweat proof Magnon Electrolyte PocketTM. Zippered small elastic mesh pocket on shoulder strap. * Sizing: Chest - S/M (28"-42"); L/XL (36"-46"). Torso Length - S/M (16"-20"). L/XL - 18"-24". Weight: 200 g (340 g with reservoir)