A premium hydration pack. Very comfortable to wear and well made. high quality. It's big, and you have a lot of room for some snacks, bug spray, some sunscreen, and any other small items you might want to take with you on your hike. There is a lot of water, enough for a day. Remember, this is a big bag. It is very comfortable to wear between the waist belt and the ventilated back. However, this is not a small fast bag, but a large bag suitable for all-weather use. For its size, it is very well cushioned and comfortable. 100 oz is a lot of hydration.