Disposable Spirometer Mouthpiece for Midmark IQspiro® Spirometer (29-8050-025). Same as Midmark (2-100-1205). SDI's SmartSense™ disposable mouthpiece is designed for use with Midmark IQspiro® devices to help prevent cross-contamination between patients and ensure accuracy at a great value. Packaged 25/box, 100/box, or 300/bx. Priced per box. Compare and Save. See "Options" above for packaging selection.