A Japanese toymaker has unveiled the world's smallest rubik's cube that costs 777,777 yen (₹4.4 lakh). Made of aluminium, the rubik's cube weighs just 0.33 grams and each face of the cube measures about five millimetres across. It broke the world record set by British puzzle designer Tony Fisher in 2016, who made a 5.6-milimetre version of the rubik's cube.