HIGH CAPACITY(8.27*3.74*3.74 in) this bike saddle bag has lots of space to hold your items. Big enough to fit a multitool, keys, levers, mini pump, phone, card and spare tube for a road bikeEASY TO INSTALL: bike bag under seat is easy to install due to the well made velcro and rubber fastener system used. Fits tightly to the saddle and seat post with no shaking. Size of bike storage bag appear to be just right for a road bikeNIGHT VISIBILITY: bicycle saddle bag has a built in LED strip light and a loop to attach an additional rear light. LED strip has 3 different variations. AAA Battery powered green light strip, lining the outside of the saddlebag adds to your bike's lighting/visibilityDURABLE AND WATERPROOF: bike pouch build with waterproof fabric, waterproof zipper, take rain cover protects your items against raindrops and moistHUMANIZED DESIGN: bicycle bag with three internal mesh pockets, be able to sort and place what you need take