A travel towel is always useful, especially if you don't want to take a huge hotel towel with you on your trip. 
During a layover, do you like to jump into lakes and go to waterparks spontaneously? The microfibre cloth can be packed into a backpack to save space and it also has a holder with a snap hook, which adapts it to any activity. 
When unfolded, the towel measures 40cm x 80cm and weighs 0.06 kg.