This is a retractable pound coin for uk trolleys that push the coin in a slot in the edge of the trolley handle. Slide the key in, push forward and wiggle and it will release the trolley, slide the middle bit back and pull out the key and put it back in your pocket.
This is a remix of pual45's version which was for another printer and i had to modify to add a gap in the jaws as they fused on the bambu printer when sliced.
there is a tiny bit of tree support to remove then push the middle bit between the jaws making sure that the plastic has all been removed from the groove.
prints fine on PLA