Ultimate Performance UP Race Number Magnets Lightweight Simple Secure Attachment for Race Numbers No More Pins Running Competing Marathon Endurance Events Black

Very strong and sturdy magnets. Used for multiple runs and no issues.

Fantastic holds the race numbers firmly in place! Highly recommended!

Have worn these for three 10K events so far, the first one with some pins just in case. Weather has been sunny and atrocious and they have done the job required. No slippage or rubbing against the skin. They are a bit fiddly as they are quite small, something a little larger would be nice.

Perfect

One fell off during the runs. Was ok as three others but number became flappy. Will go back to pins

They didn't seem strong enough to be reliable, and they'd slide around on the tshirt. Better to stick with pins or clips.

I bought these as an alternative to pins for holding race numbers on my shirt during races. Unfortunately they are not a good alternative. Though they are a reasonably strong magnet, they are just not able to cope with the movement that they would need to be able to tolerate to work well.