Go-to packThis pack has been on many adventures! Fantastic for a weekend or overnight bag, carry on, or day hikes. Enough space for camera equipment, clothing and has a separate reservoir compartment in the back. Fits osprey 3L. The "plus" pocket in the front is great for quickly getting to items in zippered area or stuffing spare jacket or hat in open area (adjustable click straps). Fits comfortably with chest (has whistle) and waist straps, you can easily clip on other items with carabineer.