Traditionally the tilt-bar in the centre of each panel is used to change the pitch of the blades by moving the bar up or down.  A new mechanism has been developed recently and is exclusive to MALIBU shutters which allows the tilt-bar to be done away with completely.   When one blade is moved, the other align perfectly through a hidden gear system in the style.  This a desirable option in modern minimalist design environments.Such an option is also suited to areas where space in front of the shutters is limited.