nxtop stainless steel wire rope crane pulley block m15 lifting crane swivel hook single pulley block hanging wire towing wheel 6pcs nxtop a crane pulley block is a kind of hoisting tool, also called a <br>sheave, is a mechanism composed of a wheel on an axle or shaft that may have a groove between two flanges around its circumference. <br><br>a rope, cable, belt, or chain usually <br>runs over the wheel and inside the groove, if present. pulleys are used to change the direction<br><br>