Nymo is a nylon mono-filament beading thread. Nymo Thread is durable, strong and easy to use once it has been properly conditioned and was specifically made for working with seed beads. B size has 65 meters and is great for a wide range of projects and is regarded as a general purpose thread, is ideal for 12/0 and 11/0 seed beads. D size has 58 meters and is great for a wide range of projects and is regarded as a general purpose thread, is ideal for 11/0 and 10/0 seed beads, and good for necklaces and bracelets. F size has 39 meters and is thickest sized and used as a heavy duty thread good for 5/0 and 8/0 pony beads. It is good as a craft thread for heavy duty sewing. O size has 105 meters and is great for earrings or any piece that requires you to thread and re-thread through a bead many times.