I think the name says it all; this is a kiteboard fin based on the Liquid Force 'GTS 2.0' model (so if you have a board that fits these you can use this 3D printed version no problems).
This is not just a test piece, but I now use these 3D printed fins on my board. I've been printing them on an 'Up! Plus 2' printer using the 0.15mm layer settings and solid fill for strength. I have also been using a small amount of acetone just to finish off the outside surfaces, but the quality off the 'Up! Plus 2' has been pretty good so you don't necessarily have to do this.
Check out my blog to read how these were developed and tested (http://edditiveblog.wordpress.com/category/kitesurfing/) All I can say is have fun out on the water, and let me know how you go!!