Surly Snuggnut Chain Tensioner Description: The 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 single-speed applications. Snuggnut is CNC-machined for durability and good looks, and shares many design features found on Tuggnut and Hurdy Gurdy. Features: Compatible with 12mm horizontal, thru-axle dropouts only Snuggnut is not for use with MDS Chips Tool-free chain tensioning CNC-machined Specifications: Color: Black