A conveyor will always consist of at least two pulleys (head and tail) with additional pulleys used depending on the configuration. Standard-duty pulleys are usually adequate for simple applications, but mine-duty and engineered pulleys are also available where heavy-duty pulleys are required. Pulleys are divided into the following sub-categories: Head pulleys – located at the discharge point of the conveyor, usually drive the conveyor and often have a larger diameter than other pulleys, usually lagged for better traction. Drive pulleys – driven by a motor and power transmission unit to propel the belt and material to the discharge. Tail and wing pulleys – located at the loading end of the belt, come with either a flat-face or a slatted profile (wing pulley), which cleans the belt by allowing material to fall between the support members. Bend pulleys – used for changing the direction of the belt. Snub pulleys – improve the traction of the drive pulley by increasing its belt wrap angle. Take-up pulley – provides the belt with the proper amount of tension; its position is adjustable. Lagging types: Diamond-shaped rubber lagging, bare lagging, ceramic lagging, spiral pulley, wing pulley, and cast polyurethane lagging pulley.