I went to make some kava with my aluballs and shaker and one of the balls had a piece of grind wedged into the edge of the filter. I threw the whole ball away and then I remembered I had saved half an aluball from a different ball that malfunctioned. I went to see if the other half would fit and it does. So I took out the good half of the ball I just discovered was broken, washed it to get the garbage germs off it and screwed on the spare half. It's a different color. That lime green with black, but I figure a mismatched ball is better than no ball. I'm glad I saved that green half, what, a year or so ago?