Use for launching surface marker buoys or lift devices in the ocean while scuba diving. They are also commonly used as replacements for jump reels or safety reels in cave diving or wreck diving. The Saekodive finger reels come with nylon line at three different sizes and they all come with a 4" double end SS bolt snap for easy storage on your diving gear. Simply remove the reel from storage, attach it to your surface marker or lift bag and inflate it for your various applications. The finger spool spins effortlessly.