Harkens beskrivning (på engelska) Small Boat Flip-Flop blocks pivot around the line axis to keep the line close to the deck. Hinged construction allows for various lead angles. Ratchamatic block versions roll freely in both directions under low loads and automatically engage a ratchet mechanism as loads increase, giving sailors a holding power of up to 15:1. The ratchet engagement can be adjusted to a higher or lower load depending on the sailors strength, sailing style and system usage.