They are the perfect thing to keep a shawl or scarf in place. The magnets are strong enough, according to the description, to hold through five layers of thin cotton. I think that may be an understatement; I have found them to hold perfectly through two layers of fingering weight wool garter stitch plus a cotton t-shirt.
Here is today's demonstration:
The second magnebutton is inside the black t-shirt. No need for a safety pin or a bulky knot, the scarf stayed exactly where I wanted it all day.
$18/set of two. This is an unsolicited testimonial; I have no connection to the site or the product except being a satisfied customer.