Khay giữ đầu vít 4mm nam châm Gridfinity (Gridfinity 4mm magnetic bit holder)

This is a 4mm magnetic bit holder with a gridfinity form, holding 99 bits in a 2x2 gridfinity configuration.

The base is meant to hold these 3M magnets.  

https://www.amazon.com/dp/B07GQQBZS3

Print the base and the insert.

Then insert 16 20x20x2mm magnets in the bottom of the base.  

Place the insert on top of the magnets in the base apply superglue along the sides to hold it in place.

The magnets should be strong enough to hold the bits in place (even when turned upside down!), but not strong enough to magnetize the bits.