Niobium Hypoallergenic Anodized Wire
Niobium is an anodized (not dyed) hypoallergenic metal developed by the NASA space program. It is an excellent choice for quality jewellery wire working. When working with Niobium cover your pliers with Tool Magic (tm) or Tape to prevent marring of the surface.
For your convenience here is the conversion scale of wire from the American Gauge system to metric (mm):
22 Gauge = 0.643mm
20 Gauge = 0.813mm