Safety, via Trabuzio
Here we see an all-steel Catello Trabuzio (also spelled Tribuzio) Palm Pistol, produced in the 1890s in Italy, the ring you see at the base of the grip is the trigger that doubles as a safety (by collapsing). Turning the safety a few more twists one can remove the cover and inspect the inside.
This repeater 8mm semi-auto uses a top-loaded magazine and incorporates a witness holes in the side for the gentleman and lady on the go to keep easy count of how many rounds they had left. This one is in the collection of the National Firearms Museum but they do pop up at auction from time to time, priced around $2K.