Migrated to: https://www.printables.com/model/541813-pantene-shampoo-bottle-funnels Pretty straightforward idea: link your old and new shampoo bottles so you can get all the shampoo into the preferred bottle (which in my case is always the one with the pump, whether that's the old or the new bottle. There are two bottle adapters here: one is for two threaded bottles (old pump bottle and new pump bottle) and one for a threaded pump bottle and a snap-on flip-top bottle. The snap-on bottle will take a firm push to go on (and as I write, I haven't separated it yet. These can just live in the shower when not in use, so they're handy, and easily rinseable.