Electrolux Perfectcare 800 washing machine foot adjuster. It's has a thin nut on the feet which is side to side 30mm (M18). This is perfect if your machine is on the floor like mine to slip under. It's just 5mm thick, so it slides under quite perfectly I printed it with 4 walls, 25% gyroid infill, PLA on a creality Ender v3 SE.