What a clever simple-but-well-executed idea for a toy: A yellow inner egg and the outer blue egg have aligning openings, but when you turn the timer at the top, they are turned away from each other and then slowly tic-toc back until the yummy stuff inside can be accessed. No batteries are needed. Made of sturdy plastic, the device is the size of a potato and weighs a bit under a pound. Sturdy and super fun!