New unused blocks in their original packaging. These retail for $899 each. They have the roller bearings that have MASSIVE load capability. Full spec for part number 3237 can be viewed on the Harken web site at

https://www.harken.com/en/shop/black-magic-air-blocks/75-mm-aluminum-double-footblock-lockoff/

I have three available. Buy one, two or three. The price is per block.