Back-friendly symmetrical design eliminates uneven weighting, chafing and uncomfortable pressure points * AirFlow MeshTM hybrid mesh technology wicks away moisture and circulates air between your back and the pack * Fully adjustable belt offers a comfortable fit * BPA-free 20 fl. oz. HydraformTM water bottle nests laterally for a naturally comfortable fit * Low-profile bottle flattens center of gravity, reducing slosh and bounce