EVOC: The JOYRIDE 4L is a lightweight performance kids backpack for bike, with outstanding carrying comfort and the same functional features as the adult models.• AIR TUNE SYSTEM offers perfect back ventilation• Compatible with optional hydration systems up to 2L• Hip belt (detachable)Material: N 210D RIPSTOP HD, 3D AIR MESH4L, 300g, 39 x 20 x 6 cm