A feet replacement for GMMK full. It was modeled after GMMK 1 full so there may be some misfits, tough it seems like they used the same one for their latest models too.
For the rubber use the one from the old feet or get some 2.5 mm anti slip rubber and cut it. Added a photo with dimensions of the hole for the rubber. It's from a top view, the side angle just cut manually.
Added a picture of the support config I used. Put high infill (I used 100%) and 4 walls. Printed on 0.08 layer line, you would be fine with 1.6.
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