The London Bus 3D Crystal Puzzle is a fun brainteaser that may invoke memories of a favorite trip (or hopes for one to come!) It is a sleek, translucent, crystalline puzzle with 53 unique interlocking pieces. When you've pieced it all together (be ready for a challenge), this double-decker bus will catch everyone's eye. This 3D puzzle has a difficulty level of 2. Assembled puzzle measures approximately 4.5 x 1.25 x 2.25 inches.