Maximum security in sports climbing the Gluebollt is Edelrids version of the classic Bühler climbing bolt. This shape of glue-in bolt was invented in the 60s by the amazing Frankenjura climber Oskar ""Ossi"" Bühler and quickly became the standard in that area. The glue-in bolt is a modified version of the original hook shape with a slanted top that prevents unhooking of any carabiner. The hookeye is large enough to take up to three carabiners. This makes withdrawing from the hook possible at any time. A round cross section lets you abseil on the glue-in bolt which is not possible with a hanger. Note: using adhesive hooks requires a lot of experience and care. These types of hooks can only be used after extensive training with a qualified professional. The climbing ethics of the area you are in should be considered when taking on new routes, and the first climber of said route should also be asked for permission. "