the "slip" of the cube is perfect, I received this morning and my son not narrĂȘte to play. And also his brothers and sister want to jouer.Un 4x4 is a puzzle that the 3x3 because a friend of my son had a 3x3 and my son did in 2 minutes, then it makes the face in 30 seconds and can not do the two sides in less than 2 minutes. I highly recommend for puzzle lovers like my son.