This is version 3.0.
The Breech is the iconic part of the Nimble.
It makes changing filament a snap and allows the filament path to be fully visible when removed. It also is a very small piece of plastic and more than any other part of the Nimble it is subject to wear and tear.
This is the Breech for the Nimble Flex (V3).
This part is delivered by Shapeways. You will need to use the original pin and bearing.