The CORNERS are used to change the directions of cable travel.
The corners are specially designed to transfer the conveyed material from one tube to the other and reduce drag on the system. This is accomplished by means of an idler wheel mounted on bronze bushings.
The idler wheel is formed to reduce buildup of material inside the aluminium housing by forcing it to the outside as the idler turns, allowing the cable to carry it away.
The aluminium housing is structured so that it can be waterproofed and so that it will hold tubes rigidly in line with itself.