 In 1971, members of a feminist reproductive health self-help group, Lorraine Rothman and Carol Downer modified equipment found in an underground abortion clinic that was developed for a new non-traumatic, manually-operated-suction abortion technique.They took the thin, flexible plastic Karman cannula (about the size of a soda straw), and the syringe (50 or 60ml), and added a one-way bypass valve, to fix two main problems.The contraption could prevent air from being pumped into the uterus, and also suctioned uterine contents directly into the syringe, thus limiting the amount that could be removed.