I would love to see skimmer carbon bag holders. Slapping a bag of carbon on the skimmer works but a 3d printed ring/bucket would be nice. In general I think a LFS could put a 3d printer to good use as they would not have to carry individual models and could just print on demand. Shipping some of the products kills the value for the consumer. I also am a sucker for sea urchin hats but I don’t know how well they would sell….