I used two standard 16mm dice and put 4 powerful magnets (not sure if they are neodymium or not, but they are certainly powerful!) in each one.
This was actually a fairly difficult mod to do. Getting the magnets to sit correctly in the die and then securing them was a pain in the neck.
My objective with these was to combine the mobieus style and the dual dice style. I’m pretty terrible at both of these things, but I’ve been able to come up with a few tricks.
Combined, they weigh a few grams more than a duncan dice. They are a great weight for DD (between a standard 16mm dice and a duncan dice).
Also, this was my first mod that landed me in the ER. Always wear your safety goggles kids