Brick shafts are LEGO®compatible shafts that you put on any of the knobs. Now you may mount any lego part. Why not put on a big lego rubber wheel for that extra grip? Or build your own motor driven programmable LFO together with LEGO MINDSTORMS? The brick shaft comes in four colors and lets you experiment with any parameter. It supports any idea you may have that involves LEGO bricks. Available in 4 colors.