This raincover is great in an emergency. Simply slide over the camera & lens & use the draw-card to cinch it tight around the end of the lens. Its large enough to take a lens up to 400mm long (thats 400mm physical length, not necessarily 400mm focal length). If desired, make a hole for the viewfinder & use the camera viewfinder eyepiece to keep it in place. Packs into the smallest of places, so you can always have one with you.