Some feet of our garden chairs did get lost. Fusion 360 and 3d printing to the rescue.
Inner dimension: 11.36mm x 24.9mm x 15mm
Outer dimensions: 15.8mm x 28.15mm x 5mm
I've attached the Fusion 360 design file so can easily adjust the dimensions.
Das Filament PETG
100% bottom part, 50% top part
Schiefergrau / slate-gray
I started with a PETG filament, printed on the hot side to enhance layer adhesion. If this will not work out, I'll replace it with ASA or ABS. Time will tell.