Disposable Spirometer Mouthpiece for Midmark IQspiro® Spirometer. Same as Midmark (2-100-1205) but NEW with Bacterial Viral Filter. SDI's Pulmoguard IQ 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/BX, 100/BX, or 300/BX. Price per Box. Compare and Save. See "Options" above for packaging selection.