Selecting the correct pulley is vital for the safety and success of a cable installation. The three most important factors to consider are:

• Sheave Diameter: The diameter of the sheave should be large enough to prevent the cable from bending too tightly. A general rule of thumb is that the sheave's diameter should be at least 15 to 20 times the cable's diameter to avoid micro-bends and fiber damage.

• Working Load Limit (WLL): The pulley must have a WLL that is greater than the maximum anticipated pulling force to ensure it doesn't fail under load. The WLL is the breaking strength divided by a safety factor (typically 4:1 for pulling applications).

• Sheave Material: Pulleys come in various materials. Nylon or aluminum alloy sheaves are highly recommended for modern conductors and cables as they have smooth, non-conductive surfaces that minimize friction and prevent damage to the cable jacket.