A concentrator stand for 8-tube PCR strips (also works on single 200-300ul PCR tubes). Works just as well as the more expensive machined models (actually, it's faster because it uses a more powerful magnet).
If you plan to use this around bleach or some organic solvents, I would suggest getting a version printed in acrylate, as it is much less porous.
30 Second assembly: just press one 3"x1/2"x1/4" N42
magnet into place (you may want to use a dab of superglue).