Respiratory Resistors Increase efficiency of ventilator testing and training with IngMar Medical's Parabolic Resistor Ring. This simple but clever tool provides a complete set of seven respiratory orifices. Select the resistor you need with a quick rotation of the ring — there is no need to disconnect tubing! Because resistors are integrated into the ring, individual resistors cannot be misplaced. Never search for a missing resistor again! • Meets ISO 10651 and ASTM Fl 100 ventilator testing standards • Calibration certificate available for standards testing INGMAR MEDICAL Respiratory Simulation Specialists