Roller: A regular pulley has a slot for a belt, chain or cable. A reel is a wider pulley generally employed in cable programs, making it possible for the cable to be wound all around several occasions the diameter of the reel.
Roller: A normal pulley has a slot for a belt, chain or cable. A reel is a broader pulley typically employed in cable systems, enabling the cable to be wound around many moments the diameter of the reel.