This is a 3D printed dial. It is a revision of Markla's which he's put a couple different sizes of onto his control mechanism of death. Seriously, I haven't sailed his boat since it was installed purely because it will cause significant bleeding if you hit it.
The dial though is great, can't believe how much better the control is over the boat with a working dial. The actual part was easy to model (rhino), cheap to print (shapeways) and fit perfectly over the existing turnbuckle that was previously only used on land or when stopped on the water.