Also known as the Guinea Feather Apparatus, this provides a great visual demonstration to teach your students about air resistance! The cylinder is capped with a hard rubber closure at one end and a hose connector at one end, which is used for air evacuation. When the tube is inverted and the air is removed, the disc and feather will fall at the same rate as the feather does not meet any air resistance. 36" x 6" x 6"; 2 Ib