Magnetic Pick-up Tool

I've found a magnetic ferrite ring in my hardware shop and I've decided to make a Magnetic Pick-up Tool (I don't even know if it's the real name). Basically, it's just an handle with a magnet at the end, usefull to find lost screw or other metallic stuff dropped.

The magnet I've found have a 22 mm internal diameter a 50,5 mm external diameter and a "thickness" of 10 mm. I don't know if there is a "standard" for magnetic ring, but If you find a magnetic ring with different size, feel free to a