Harken ball bearing 150 cam cleats hold lines securely and release instantly for easy, precise trimming Aluminum Cam-Matics are hardcoat-anodized for high-load, high-wear, continuous adjustment applications First are the 33 ball bearings in each cam, stacked on three levels to balance and start them moving so easily. Next, the top of each cam is shaped to allow even a loaded line to drop in from above rather than having to pull them open. Then, there’s the cam radius which enables them to hold a wide range of sizes while still being kind to the line.