These are small rounded 304 stainless steel lever back ear wires with an open loop.
They measure 13x10.5mm and will sit close to the bottom of the ear lobe so that less of it shows in your overall earring. These have and open loop so that you can easily attach another closed loop item, such as a charm, directly to the ear wire.
The loop is about 1.5mm and the thickness of the wire going through the ear is 0.7mm.
Stock up with the lot of 100 pieces!