Takes up to nine, 8x3mm magnets. I secured them w5-minutenute epoxy. I do not recommend superglue for this type of application.
These magnets are strong, so I thought I would be fine with 5, but I used 9 thinking it would be super strong.
But, even with 9 magnets, it still slides down a little but if I drop the screwdriver in at all. I'm not sure if they just aren't making good contact, or the shelf I have it on is just slippery or what, but I'd recommend using all 9 just in case.
The author remixed this model.
I simply covered the old holes and made new ones for 8x3mm magnets instead of 6x2mm ones.
I could have cleaned up the mesh quite a bit, but it didn't affect the print, so I didn't bother.
I've included my blender file in case anyone else wants to modify it for different sized magnets, or whatever.