The standard Frosty plastic bobbins have a large capacity and are very durable. You can even dye and boil them with your yarn still on the bobbin. Majacraft Spinning Wheels come with at least three plastic bobbins.
The new standard plastic bobbins are molded in ABS plastic which lessens the noise made by the tension string in the groove.
Cutouts in end the end plates decrease the weight and allow a view of the yarn on the bobbin when spinning.
Polymer bearings have been added inside the bobbin to add strength and durability.
The added drive pin holes make these plastic bobbins compatible with the Aura.
Standard Black Plastic Bobbins can be found here.