1D20 of Holding (with Magnet sockets)
Simple Remix of the D20 of holding to add sockets for magnets.
Sized the holes to fit 5/16th diameter, and 5/64ths inch thick rare earth magnets .
You can get that size really cheap @ any Harbor Freight Tools, https://www.harborfreight.com/10-piece-rare-earth-magnets-67488.html (2.99 for a 10 pack)