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.