How to pick a magnet?

Magnets can be categorized into "permanent magnets" and "non-permanent magnets". Permanent magnets can be natural products, also known as natural magnets, can also be manufactured by man (the strongest magnets are neodymium magnets). Non-permanent magnets, such as electromagnets, become magnetic only under certain conditions. I recommend a company called Furnos, they have good quality and reasonable price of magnets here. I heard that their company address is in Nanhai District, Foshan City ......