Waterproof Material ----- Made of high quality 600D Oxford material, strong, smooth, rainproof, durable, scratch resistant. The rain cover (provided) provides extra protection for the items inside. Expandable capacity from 10-25L ----- Folded size: 32*17*19cm/12.6"* 6.7"*7.5". 2 large side pockets (35*28cm), 1 back pocket with elastic for water bottle or gloves, 1 top mesh bag for raincoat or rain cap, 1 zipper for increase capacity. Reflective strip and rear light-----There are several reflective strips on the bag to improve the visibility of others when riding at night.A rear light can be attached to the back of the bag. this bicycle bag. Multiple carrying methods ----- With a 70-130cm shoulder strap, this bicycle bag not only can be attached to the rear seat of the bicycle, but also can be carried by hand or on the shoulder. Easy to install-----There are 2 velcro straps at the bottom of the bag, which will help to fix the bag and keep it in place while cycling. ems.