This is simple adapter for standard channel fan with 100 mm out to 30 mm pipe to be used with 3/4" water pipe adapter (http://www.thingiverse.com/thing:39745).Set walls thickness to 0.8 mm and print with normal or high quality. This thing developed to be used with 3/4" water pipe adapter you can find here: http://www.thingiverse.com/thing:39745Note: if you want to print directly from .STL file you'll need to flip Y-Z planes to place thing correct on printing table.