sensor for arduino nano to count spins

Hi guy's

i am looking for a sensor to connect to the arduino nano,

i need to count spins and show them on small screen LCD with numbers.

can you help me to understand what kind of sensor do i need?

i should be able to count the spins of the object that it glue to it also while it spinning in the air..

thank you !

A stationary Hall sensor may be a good idea, with a tiny magnet on the part that moves.

I use that idea to measure the speed of a continuous servo motor. I glued the sensor to the servo’s body, and glued the magnet onto the servo’s arm.

Optical may also work. It's all depending on the size actual object, the speed it rotates at, the things you may or may not attach to it, the distance at which it has to be read, and probably some other parameters.

As you didn't tell ANYTING about the object in question and how it rotates ("in the air"?? Magnetic levitation? On a wire?) there's nothing much we can say.