the Harken 16mm Flip Flop Block offers a user-friendly and versatile solution for controlling very thin lines on sailboats. The combination of a compact size for tight spaces, a small sheave for thin lines, a low-friction bearing system, and a flip-flop base for adjusting lead angles or fitting in tight spaces makes it a valuable addition to control line systems on dinghies, specific lines on larger boats, and applications where minor adjustments to line lead angles are desired.