Durable nylon construction with heavy duty water resistant coating and weather proof zipper help keep items dry * Equipped with reflective piping and rear light loop to attach safety light for added visibility * Velcro webbing side straps secure bag quickly to saddle seat rails * Zipper on lower section opens to allow bag to expand adding another 70 cubic Inch of storage * 90/160 cubic Inch * Zipper on lower section opens to allow bag to expand adding another 70 cubic inches of storage