Ambidextrous AK fire selector. Designed for an AK-63F, so it should fit the vast majority of AK-pattern rifles.
It works for all three positions, but it's practical only for semi-only rifles, since the angular rotation between the two fire modes is so small, that it is hard to set it with your thumb. But it is fine for changing between safe and semi.
This serves mostly as a proof of concept, but as long as it doesn't get too hot, it should be functional. Not tested. Printed in Creality HyperABS.