Load all your large-arbor fly reels with backing, line and power. Team the Large-Arbor Loader with a 7/16" nut driver (not included) and a cordless drill or screwdriver (not included), slide the reel handle into a slot and you’re ready to go. Fits a wide range of large-arbor fly reels. Will not mar your reel’s finish. 5.5" outside diameter.