The Harken 40mm 90 Degree Fixed Head Carbo Block is a reliable and affordable option for controlling lines on sailboats, particularly for applications requiring a 90-degree change in line direction. The combination of a low-friction Carbo sheave for smoother operation, a fixed head for simplicity, and a compact size make it a valuable addition to any control line system on smaller and medium-sized vessels, especially for those looking for a cost-effective solution.