Controlling blinds, wich module do I need?

[Duggel]

I have manual-controlled venetian blinds. To open and close these blinds I want to build a motor into the housing.
To control the motor fibaro has 2 components wich can do this:
The Fibaro Roller shutter module and the Fibaro relay module.

My question:
The Roller shutter module is (based on it's name) the module I need, but the relay module also has an option which can be set to roller/shutter control.
What is the difference between these two modules?

Thanks for the help.