The Schacht High Speed Bobbin is made of hard maple or cherry with a hand-rubbed Danish oil finish. It has a 4-ounce capacity. The High Speed Bobbin can be identifed by “HI SPD” written on the small end of the bobbin, but otherwise looks just like the regular Spinning Wheel Bobbin. The High Speed Bobbin is required when using the high speed or super high speed whorls in double drive.