Main Features:￠ Material: water-resistant nylon cloth with double-wall TPU・ durable and not easy to deformation￠ Reflective LOGO and letter pattern for increasing the safety of night cycling￠ Quick-release design・ nylon loop to fix the bag into the tube・ easy to install / remove￠ 3 - 10L adjustable capacity ( depending on how many times you roll the sealed buckle ) for storing key・ pen・ mobile phone・ towel・ bike repair outfits・ flashlight・ etc.