Achieve perfect spoke tension with the Park Tool Master Spoke Wrench. This three-sided spoke wrench is made of heat-treated, polished and plated steel, which maintains robust durability through years of bike maintenance. It's designed to fit in your hands for adeptness while you're adjusting wheel spoke tension. The SW-20 adjusts 0.136-inch (3.45 millimeter) spoke nipples, while the SW-20.2 and SW-20 adjust 0.127-inch (3.23 millimeter) spoke nipples.