FingerThinkers™ are little leather thimbles with magnets attached to be used to help children learn. It's supposed to work on the same principle as tying a string around one's finger. The magnet is very important to the design because it is smooth and cool and pleasant to touch, which can be easily accomplished in a "rhythmic motion that tends to be comforting and relaxing in nature," thoughfully illustrated on the website (shown at left).
FingerThinkers™ may be purchased as part of a kit; there are 26 Fingerthinkers, 1 storage container (plastic bucket), and 2 classroom banners ("Are you using your FingerThinkers™ today? Remember to use it when doing homework too!" and "I become a better thinker when I use my FingerThinker™") per kit. The kits are $258.70, but there is a 50% discount when purchased directly by schools or school districts. One can purchase the FingerThinkers™ separately (without storage container or banners) for $4.00 each, minimum order of 26.
The website has several comments from teachers who'd participated in a study about the FingerThinkers™. My favorite: "It certainly couldn’t hurt."