Double Trouble is a set of two twisty puzzles, based on an idea by Bram Cohen. The two cuboid puzzles seem to have the same behavior at start.
-The green and blue faces turn freely
-The yellow and white faces are coupled to each other
-The red and orange faces are completely blocked.
A difference arises when one turns the coupled yellow and white by a quarter turn. Then
-in version A, the red and orange faces remain blocked and the green and blue faces can still turn freely, whereas
-in version B, the green and blue faces become locked and the red and orange faces can suddenly turn freely.