The Calibration adapter is specially designed to help connect the 3-liter syringe to your EasyOne and to facilitate a calibration check function.  Adapters should be used in conjunction with Calibration Syringes, making it easy for you to check your Spirometer's accuracy in a few simple steps.  Designed to be reliable and provide the additional support you need, each Calibration adapter is made from high-quality, medical- professional grade materials to ensure you can always depend on it to provide accurate results.