Size 9.6x2x1cm, Packing 16.5x9x1cm, PVC
A rattleback, also known as an “anagyre”, “celt”, “Celtic stone”, “rebellious celt”, “rattlerock”, “spin bar”, “wobble stone” or “wobblestone”, is a Celtic science curiosity whose ancient and mysterious properties capture the attention of all ages for thousands of years for its apparent defiance of the laws of physics. It spins one direction only: if you spin a rattleback in clockwise, it would spin as expected; if you spin it in anticlockwise, it will quickly come to a stop, oscillate and then start spinning in the opposite direction ! If you tap lightly on one end, it will start spinning.