Low Friction Ring - 16mm Hole. Low Friction rings can be used as a lightweight alternative to a block in some applications. They are best suited for systems requiring relatively small line deflection angles, or for high static loads.. The design achieves a nicely rounded internal profile for smooth control line trim under load, and a deep external groove to retain the rope securely within the large shoulders when spliced into a loop.. Features:. Compact & lightweight. Low friction. Large shoulder secure allowing for rope lashing. Durable. Simple & reliable design. Low maintenance