This is a small CamelBak backpack. I used to love using it when riding my mountain bike. Therefore, it has some dirt. The capacity is 10 liters. The lower left and right wings, which also serve as small item pockets, adhere to the waist, creating a sense of unity with the body. The back is designed with ventilation in mind, preventing stuffiness. I'll include the original hydration pack, but it has been repaired with glue and tape in one place, so please consider it a junk item/bonus.