?Liftable Biplane?: Movable airplanes on rotating tower, real and interesting. ?Gear-Transmission?: Gear drive mechanical model, experience the magic of mechanics. ?Wind Up Musical Mechanism Movement?: Manually to rotate the knob, then release, the music will be playing. ?No glue needed?: Consists of 255 pre-cut small wooden pieces, needs to be assembled by yourself. No glue needed at all. ?Clear Instruction?: Step-by-step, easy to follow assembly guide is included, makes the whole assembly process much easier and enjoyable.