For measuring tidal volume and respiratory minute volume. One-way valves enable subject to inhale room air and exhale directly into lung volume bag. Volume is read directly from wall of bag (scaled in 100-mL increments up to 6 L). Includes 2 one-way valves, T-adapter, lung volume bag, 3 reusable mouthpieces, mouthpiece holder, and 30 disposable mouthpieces. Order item# 692647 Mouthpiece Replacements.
