Prank Pipe

thingiverse

Originally crafted as a device to measure lung capacity, this Spiro meter is capable of surprising users with its unique functionality. To test its effectiveness, simply exhale normally into the device and watch as baby powder sprays directly onto your face. Next, demonstrate that it really works by covering the pipe with your lips and sealing the small hole in front with your tongue. As you do so, the fan will begin to spin, a remarkable feat that showcases the ingenuity behind this cleverly designed gadget. One of those intriguing devices that reveals its secret only when manipulated in just the right way...