HARKEN 16 mm Classic Triple Block, 408 Sailboat Blocks & Hardware_40 mm Double Carbo Block - Becket Commonly 57mm fiddle blocks are

Commonly 57mm fiddle blocks are for jibsheets and vangs on small dinghies

which is a line of hardware that complements other existing blocks in looks but is simpler in design and construction

cascade system boom vangs

The block headpost fits into the socket without a shackle

The 438 adapter plate is perfect for mounting on masts and booms

HARKEN 16 mm Classic Triple Block, 408 Sailboat Blocks & Hardware_40 mm Double Carbo Block - Becket Commonly 57mm fiddle blocks areHarken 16mm Triple Block is Harken's smallest, with sheaves that are only 5 8" in diameter 16mm Blocks have a lightweight design and a unique patented bearing system that uses stainless steel balls in a captive, grooved race. Very high working loads in an extremely lightweight block, with the best strength to weight ratios around. Use with small synthetic control lines found on high tech dinghies.