Bought these for my husband and he wears them all the time!
Power Stays, Assorted Sizes: 2.0, 2.5 & 2.75 inch (Three Pair)
I have been using these for several years now. Magnets are super strong. In an age when professional does not require a tie, these are a god send! I hate button down collars, but want to look neat. I used to have to finagle a safety pin to hold my collar down. These make a world of difference. The only downside is that I do need to replace periodically... not because of durability, but the magnets can easily be lost. I have been averaging one set of three per year.