What is the difference between a Pro Frame and a Simple Frame?

The difference between the Pro Frame and the Simple Frame is the lowering and raising mechanisms inside. The Simple Frame runs using a Single Motor Mechanism on one leg and connects to the other leg by means of a drive shaft and a gearbox which causes the desk to go up or down. The Pro Frame runs with a Dual Motor system. It doesn't need a drive shaft to relay movement to another leg. Each leg has its own motor and can move a lot smoother than it's predecessors. Having motors on each leg distributes the stress and weight carrying capabilities making it a better choice for having desktops, multiple monitors or having heavy loads on your desk.