Obviously appears to be very thin walled.
Quite a few moons ago, there was a member here that was designing, or showed a picture of his phenolic break tips with a little tail on them.
I have no idea if this was done by a cue company or this was something of his design.
But obviously a little pocket in the middle, and a deeper hole that has been drilled or bored beyond that.
There was a Cue Maker from Calgary, and now, cannot remember his name. A few guys in town do have his cues. His ferrule system that he uses is quite unique just the same.
I replaced a tip on one shaft and drew a small design of how he may have designed the ferrule. As there could be 2 different possibilities on how it was made. And by just taking the tip off, it still didn't show allow you to see how it was put together.
Ahhh, remember now. Bernie Mickelson, I think.