 They added two lengths of clear plastic tubing, one from the cannula to the collection jar and another to go from the collection jar to the syringe.With this new set-up, the contents of the uterus went directly into the jar, allowing for the extraction of more material, and the two-way bypass valve diverted any air that may have been inadvertently pushed back toward the body to exit harmlessly into the air; this would prevent air from entering the uterus.Rothman and Downer dubbed the new invention the "Del Em."