No more water all over your laboratory. Measure lung capacity without the mess associated with water displacement spirometers. This compact, rugged spirometer is as easy to work as it is to breathe. Simply put a disposable mouthpiece on the spirometer and blow into the device. The built-in gauge stops at maximum lung capacity and will stay set at maximum capacity until you reset it for your next trial. The easy-to-read gauge is calibrated in 0.1 L units from 0.0 to 7.0 L.The device is especially useful for comparing lung volumes between students and for calculating average volume and variance between trials. Comparing volumes before and after exercise or when using other student-designed experiments becomes fast and easy. Trials can be conducted in a fraction of the time required by water displacement systems. Comes with vital capacity charts and 50 disposable cardboard mouthpieces.