Thank you for viewing! This is the Cool Rucksack from Ryokatsu Honpo. [Brand New] Features a TPU cooling pillow and adjustable straps for easy use. Can be used with: Rucksacks! School bags! Strollers! - Size: Approximately 25cm x 22cm - Color: Blue Gray - Material: TPU (Thermoplastic Polyurethane) - Features: Cooling function, adjustable straps - How to use: Cools automatically if the temperature is below 28°C. Rapid cooling is also possible using a refrigerator, freezer, ice water, or cold water. Price is not negotiable. Immediate purchase is welcome ⭕ If you have any questions, please comment.