Zircon 57mm 1-disc block

Zircon blocks are the most efficient blocks Harken has ever made for small boats.

The basis of Zircon blocks are industrial ceramic ball bearings placed in special bearing cages.

The cages keep these bearings apart so they do not touch each other.

The result is a very free-running block with less energy loss due to friction than even in our current Carbo blocks.

Zircon bearings are more than 700% stronger in compression than stainless steel bearings of the same size.

So they will not deform if used within the recommended load.