The Park Tool SW-42 Four-Sided Spoke Wrench uses a unique four-sided design providing extra strength and support to prevent slipping and deformation of aluminum nipples. Uses the same world famous design and high quality materials as our three-sided spoke wrenches. Park Tool SW-42 Four-Sided Spoke Wrench Features Sized for 0.136" (3.45mm) nipples Same size as the SW-2 (red) More info