They are rotary beaters.
The one on the left is all metal.
The one on the right has a wooden handle and a wooden knob.
The wood had paint on it once upon a time - but is now bare.
I love these implements. Wouldn't be without them.
Great for whipping cream, eggs (whole or whites only),
and for batters and beating lumps out of liquids.
They are the greatest for providing aeration in sponge cakes.
There are other rotary beaters around - but not all are equal.
This design is the best.
Straight up and down from handle to beater.