Our iconic spoke wrenches have been a mainstay of our product lineup since we introduced them over 50 years ago. With their simple design and professional quality, they're still the favorite of bike mechanics around the world. Each Park Tool SW-6 is made in the USA, and is heat treated and nickel plated for long service. Park Tool spoke wrenches are vinyl dipped to indicate the size at a glance. - Sized for spoke nipples with 3.7 mm (0.146") wrench flats - This size can be found on some hub-drive e-bikes -- always measure to be sure