This is an alternative spacer for Ikea Skadis with a length of 24mm.
This spacer kann be used with the orginal Ikea screw or just with any M4 screw.
It has a printable thread. But if this doesn't work for you, you can press fit a M4 nut instead.
The original spacer is 20mm long. When I mounted the Ikea Skadis to the wall there was a little gap between the wall and the end of the spacer. That's why here is an alternative version which is just 4mm longer.