Fiddle blocks have sheaves that are mounted on top of each other, making this type of block ideal for tackle assemblies, especially when the fixed end of the line is attached to the fiddle block with a becket. Fiddle blocks may also have a cam cleat for use with main sheets and boom vangs. When buying a fiddle block, make sure you get the right size. Whether with a swivel, cleat or shackle, we have everything you need on board.