This is the Park Tool SPA-2 Pin Spanner. Park Tool pin spanners are durable, easy to use and color-coded, so you know which one's which. Park Tool Pin Spanners have been designed to give maximum usefulness and versatility at the lowest possible cost. Tough, high carbon tool steel is used on each tool to ensure long life. Handle is vinyl coated to give a good grip. Each Pin Spanner is color coated for easy recognition. Features SPA-1 (Green) has round pin ends with a diameter of 2.9mm and fits many adjustable type bottom brakcets SPA-2 (Red) fits one-key release retaining rings on Shimano and Campagnolo cranksets and the adjusting cone on most freewheel clusters (not freehubs), round pin ends diameter of 2.3mm