The Park Tool Adjustable Spanner is made to securely fit pin holes on the retaining rings of self-extracting cranksets like Shimano, SRAM, and FSA. Its adjustable nature makes sure it can fit virtually any retaining ring. This version is best for 2.2mm pins and is made with heavy duty material to ensure a long life. The Park Tool Adjustable Pin Spanner is a great way to service your crank.