The Manfrotto #115 is a tripod head with twin adjustment levers for rotation along two axes, with a T-shaped camera screw mounting point. Its levers are known as the R3,2830. M8 Ratchet Handle and can be found here: https://www.manfrottospares.com/115-parts.html
This part replaces the end cap which retains the lever retention spring and the lever body itself into the center splined screw. If you have lost the end cap this can be pressed into its place.
You will need a well calibrated printer to get the fitment right, and a firm hand to press it on. Consider printing at +1% scale if it's too tight, or -1% scale if it falls off. This part prints exactly right on a Prusa MK3S+.
The author marked this model as their own original creation.