It's a bag, approximately 30cm wide, 33.5cm tall, and 10cm deep at the base. It's unused, but perhaps due to a Totoro-esque aesthetic, it has a slightly dirty appearance from the start, which I didn't like, so I never used it. It's not made of fabric, but a vinyl-like material. It's lightweight (around 130g) and can be folded, so it's suitable for lessons or as a side bag.