We independently review everything we recommend. When you buy through our links, we may earn a commission. Learn more› By Elissa Sanci Elissa Sanci is a senior writer who has reported on label makers, ...

[u407]’s 3D printed Signspinner was created as a clean/dirty indicator for a dishwasher, and at its heart is a mechanism that works a lot like that of a retractable ballpoint pen. Every click of the ...