Yume Group Back Cooling Pad Back cooling pad with natural cooling function that can be used at 28°C or below, attachable to backpacks and school bags. - Product Name: Back Cooling Pad - Cooling Temperature: Usable at 28°C or below - Application: Attachable to backpacks and school bags - Size: Approximately 24 x 27cm - Features: Natural cooling function I opened the bag once to check it, but it's unused. Thank you for looking.