1.WATER RESISTANT FABRIC: PU synthetic saddle bag's high-density waterproof material and rubber water resistant zipper are impervious to rain, protect valuables from water, dirt and dust, and ensure safe drying of items. The surface can be easily cleaned by wiping with your hands.2.LARGE CAPACITY:The size of bike saddle bag is 8.3 x 3.4 x 4.0 inches, the main pocket can hold keys, gloves,raincoat, mobile phone,bike tire repair tool kits,cycling accessories,etc. There are three elastic mesh pouches inside the main pocket, which can be used to hold some valuable small items. This design can effectively prevent the internal items from falling when the waterproof zipper is opened.3.SAFER RIDING:The rear of the bicycle seat bag is equipped with a safety light stand, so you can install a bicycle tail light (not included) to ensure safer night riding.