[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 bike EASY 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 bag appear to be just right for a road bike "NIGHT 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 bikes lighting/visibility" DURABLE AND WATERPROOF: bike pouch build with waterproof fabric waterproof zipper take rain cover protects your items against raindrops and moist HUMANIZED DESIGN: bicycle bag with three internal mesh pockets be able to sort and place what you need take]