ZW SS .Ant .019×.025 SS Pos.018x.018 36m Upper - PK/5

IOS, PC · #13-610-111 · source

With technology advancement, the dream of having two wire sizes or materials built into the same arch wire 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