It will thread very fine needles (size 9-12).
The case slides open to reveal a clever mechanism.
Simply insert the needle and lay the thread in the groove.
Pressing lightly on the lever directs a shaped pin into the thread through the needle eye.
If the pin hits resistance it will stop, preventing it from breaking.
The case will hold needles and the top has a magnet so you can easily pick up those small needles.
Refill threader available.