Voldyne® incentive spirometers help patients increase lung capacity through voluntary pulmonary exercise. A volumetric white piston and sliding yellow pointer make it easy for patient and therapist to monitor inspired air volume and flow. The Voldyne® 2500 low exerciser measures up to 2500ml of inspired air, making it ideal for geriatric patients or patients with small lung capacity. The Voldyne® 5000 large volume exerciser measures up to 5000ml of inspired air. For single patient use only.