The fishing magnet is a practical product for those who have lost keys / other metal objects, but can of course be used for other needs as well. The diameter is 105mm and is 20mm thick. The advantage of a ferrite fishing magnet is that it does not rust. The fishing magnets with the neodymium magnet need to be wiped off after use so that they do not rust over time.
Stated force applies in ideal conditions on a 10mm thick iron plate, without safety factor. 1kg ≈ 9.8N (Newton).
Note that holding magnets releases at given strength (in ideal conditions). Always use some margin.