Medela® Pump In Style® Tubing is used on all models of the Medela® Original Pump In Style® , the Medela® Pump In Style® On-The -Go-Tote , and the Medela® Pump In Style® Backpack breastpumps. Two tubes are needed to double pump with the Pump In Style® breast pumps. They are clear plastic tubes, with one soft end and a cream colored hard carbonate-free plastic adapter on the other end. The hard adapter end of the tube is plugged into the back of the breastshield connector, and the plain end of the tubing attaches to the breast pump. Contains: (2) Tubing per bag.