The Vyaire Medical AirLife Volumetric Incentive Spirometer is well-designed to hold comfortably while performing deep breathing therapy. Using a Spirometers improves breathing by encouraging slow deep breaths that strengthen the lungs by opening air sacs. With regular use it will improve lung capacity and keep lungs healthy.This AirLife Incentive Spirometer offers dual-sided calibrations making it easy for the patient to read the volumes that reach up to 4,000 mL. The goal indicator is positioned at the desired volume capacity to incentivize a target to strive for. As the patient breaths into the flexible tubing with adjustable mouthpiece, it lifts the indicator ball. When patient can no longer breathe out, they hold breath for a few seconds before breathing out slowly. It is recommended to cough after each interval to remove mucus. Intervals of 10 are recommended for each session. The goal indicator is adjustable to increase volume capacity as lung capacity improves.AirLife Incentive Spirometer 4,000 mL Capacity is available with one-way valve (Vyaire Medical 001901A), or without valve (Vyaire Medical 001902A). To prevent respiratory infection, this product is intended for single patient use.Features and Benefits Easy to Perform Breathing Exercise Erogonomically Designed to Hold Adjustable Goal Indicator Latex-Free Easy to Read Calibrations Adjustable Mouthpiece with Flexible Tubing Contact UsWe can be contacted directly through eBay messages if you have any questions, concerns, or requests. We will do our best to take care of you! If you receive a damaged or incorrect item, please contact us to resolve the problem. There is never a reason to leave negative feedback with us because we are always there for you if any issue may arise! We’re not happy unless you're happy! We're only a phone call or message away!Shipping FREE SHIPPING is provided on all our orders! Also, all orders received before 3:00pm CST ship out the same day!Expedited and Over night ship options are available on most all our products. If you don’t see the option available, please contact us!Returns You can return a product for up to 30 days from date of purchase. Please do a return request from your eBay account under Purchases, this will allow us to provide you with a prepaid return label. You are welcome to contact us if you have any questions.Thanks for shopping with us!We have been in business for over 39 years, and we certainly appreciate your business! Click here to visit our Ebay store.