The High Speed Bobbin is made of hard maple with a hand-rubbed Danish oil finish. Like the regular Spinning Wheel Bobbin, the High Speed Bobbin also has a 115g capacity. 
The High Speed Bobbin is required when using the high speed and super high speed whorls in double drive.  Compatible with Matchless, Flatiron and Ladybug wheels. The High Speed Bobbin can be used on the Sidekick spinning wheel but is not needed.