CamelBak: Changes in terrain demand flexibility. The Octane™ 18 sends you off with all the necessary bells and whistles - actual safety whistle included. Stay hydrated with a 2L Crux™ reservoir with Quicklink™.  Enough storage for snacks and essentials, and a convenient stretch overflow pocket for your top layers. Top load access for quick and easy stow on-the-go. Trekking pole attachment, dual adjust sternum straps for stability, and strategic 3D mesh venting for optimal air-flow while you move.FEATURES3D Vent Mesh: For lightweight comfort and air flowDual Adjustable Sternum Straps: Offers a range of adjustments for a custom fit and increased stabilityFuel and Gear Storage: Multiple stow options, easily accessibleEssentials Org Pockets: Keeps your small essentials organized and secureStretch Overflow Pocket: Quickly stash or shed an extra layerSecure Phone Pocket: Keep essentials safe and easy to accessTrekking Pole Attachment: Easily attach and remove poles when neededQuick Stow™ compatible: Carry soft flask, extra hydrationTube Trap Management: Keeps your tube secure and accessible when you need itReflectivity: For low light safetySafety Whistle: Be heard in case of an emergencyMade with Ultra Light Materials SPECIFICATIONSCOLLECTION: HIKEACTIVITY: PACKSUSER: UnisexHYDRATION CAPACITY: 70 ozHYDRATION TYPE: Crux 70 oz Reservoir, StandardBPA/BPS/BPF FREE: YesQUICK LINK DISCONNECT: YesGEAR CAPACITY: 16L/970 cu inPACK WEIGHT: 410g/14ozDIMENSIONS: 41 x 24 x 26 cmFITS TORSO: 43-53 cm/17-21 inBACK PANEL: N/ANUMBER OF EXTERIOR POCKETS: 11