This a hockey stick extension for most senior hockey stick shaft (tested with Bauer Nexus E5 Pro).
However, it can be adapted to other hockey sticks and for other extension lengths.
Leave a comment if you need help in this department.
The important aspect here is that the provided print profile uses 100% infill that spans only 50mm of the portion of the extension.
This ensures that the extension is the strongest where it interfaces with the original stick frame but can be lighter elsewhere.
I've played over 5 hockey games with this extension now and am very happy with the result.