For those occasions when you're carrying more than one lens, the Canon EF Lens Changing Kit Adapter v2 from Peak Design will help you change lenses faster, and with added versatility. Simply attach the Lens Changing Kit to a backpack, strap, bag, or belt. With this kit you can change lenses with one hand and have a convenient place to store the lens you just removed. By storing the lens outside of your camera bag you will free up space for other gear.