The effect: You have two strings of different colors that pass through two plastic blocks. Pull the two strings one after the other to show that they actually pass through the blocks. Now just slide the blocks from top to bottom so that the strings always change position! Features : – The object works on its own and you can repeat the change of place as many times as you wish.– The blocks measure 5.5 cm (2.16 \”) x 1.2 (0.47\”) x 1.2 (0.47 \”). As it is a pocket game, you can still Take it with you!