Surly Snuggnut keeps your rear wheel from slipping forward in the dropout under the pedal load from your powerful quads. It's specifically designed for Surly bikes featuring 12mm horizontal, vertical-slotted dropouts, and is particularly suited for singlespeed application. Snuggnut is CNC-machined for durability and good looks, and shares many design features found on Tuggnut and Hurdy Gurdy.