A crane pulley block is a kind of hoisting tool, also called a Sheave, is a mechanism composed of a wheel on an axle or shaft that may have a groove between two flanges around its circumference.
A rope, cable, belt, or chain usually runs over the wheel and inside the groove, if present.
Pulleys are used to change the direction of an applied force, transmit rotational motion, or realize a mechanical advantage in either a linear or rotational system of motion.
Designed for use with rope or cord in indoor and outdoor applications, but only pulley here, rope is not included.