Yazzonic Tee Joint

Not strictly a derivative, but serves a similar purpose.

I need a thing that can hold onto a bushing on one side, and perpendicular to that, can hold onto a rod of a specified size.

The default sizes for this thing is 5/16" on one side, and 11mm on the other. The bushing I am using has an inner diameter of 1/4", and outer diameter of 5/16". On the perpendicular, I'm inserting a carbon fiber rod that has an outer diameter of roughly 11mm. That rod can be friction fit, or glued, or whatev