Coupling Mechanism

This unit is composed of:
Two outer discs made of aluminum.
A central disc made of acetal, located between both outer discs. Torque transmission is accomplished by mating drive keys of the central disc, located on opposite sides and oriented 90 degrees apart, with the slots of the outer discs. It acts as the torque transmitting element. 
Both outer discs are mounted in two rotary elements with a graduated disc to read the angle.

The main metallic elements are made of anodized aluminum.
The unit is a bench top-unit with an anodized aluminum profile structure, and painted steel panel.