This is the connector that holds each part of the tail together. The original model has weak tabs that are prone to breaking. I redesigned the part with stronger locking tabs.
I had a functional print at .4 mm nozzle (recommend .2 mm nozzle), .2 mm layer height. Printed with supports. It is intentionally a snug fit so that it doesn't break apart so easily.
The author marked this model as their own original creation.