The Spiro PD personal spirometer is a hand held device that is used to test the user’s lung capacity. Measures of air flow and volume are indicators of lung health. By blowing into the tube of the Spiro PD the user can see a measure of his/her forced expiratory volume for one second (FEV1), forced vital capacity (FVC), FEV1/FVC ratio, peak expiratory flow (PEF), and forced expiratory flow from 25% to 75% (FEF 25/75). The SPIRO PD spirometer is intended to be used by a patient under the instruction of a physician or respiratory therapist to test lung function in child, adolescent and adult. It is intended to be used as a single-patient device only and can be used in any setting - home, factory, hospital or physician's office. The SPIRO PD spirometer is indicated for the following age groups: • 2-12 years - Child • 13-21 years - Adolescent • 22 and over- Adult.