Review (4/5): Apparently for Listerine bottles only.  Not universal fit.
Seems decently made.
I can confirm that this pump does not mate with Costco's Kirkland brand of mouthwash in the 1.5 liter bottle, No surprise there. The listing does specify Listerine. I'll buy :Listerine and reuse the bottle with the Costco or Sams Club mouthwash.