The design of the Spillnot uses the principles of Newtonian physics to keep the liquid in the container. The flexible handle and location of the suspension point above the center of the tray ensure that the forces on the liquid are always directed toward the supporting tray, even when the tray is in motion. Sideways forces usually responsible for spills are not transmitted to the tray by the flexible handle. Radial forces generated during swinging motion only force the liquid into the container more firmly. An inexpensive demonstration to intrigue students and challenge their analytical powers! Includes activity guide. 5″ x 5″ x 9″. Weight: .25 lbs.