This Guinea and feather apparatus uses a 100cm long, 44mm outer diameter acrylic tube fitted with two rubber bungs — one carrying a stopcock — and 60cm of tubing for connection to a vacuum pump. The acrylic body is lighter and more shatter-resistant than an equivalent glass tube. A classical physics demonstration: inside the evacuated tube, a dense object and a feather fall at the same rate, illustrating that in the absence of air resistance all objects accelerate equally under gravity. Well suited to physics classrooms exploring free fall and Galileo's principle of equivalent acceleration.