ZW BiTi .Ant.017×.025 Niti .Pos.016x.016 34m Upper - PK/5

With technology advancement, the dream of having two wire sizes or materials built into the same archwire becomes a reality
The anterior segment is thicker to maintain torque while the posterior segment is thinner for less friction during retraction.
Joining hook could be used for elastics, coils or lacebacks.
Size is measured by the distance between the inter-hook.