unlike the flat-sided v-cube 6, the v-cube 7 is noticeably rounded. this departure from a true cube shape is necessary, since the mechanism used on this puzzle would not function properly with layers of identical thickness. other means (such as magnets) would be required. note from the image at right that if a 7×7×7 were to be constructed with layers of identical thickness the corner pieces (shown in red) would lose contact with the rest of the puzzle when a side was rotated 45 degrees. the v-cube 6 and v-cube 7 both solve the problem by using thicker outer layers. the rounded shape of the v-cube 7 results in corner stickers that are similar in size to the center stickers, which helps hide the unequal thickness.