These shelf brackets are designed especially for deeper shelves with an expected uneven load across the depth of the shelf
ie. in places there will be a greater weight on the front and in other places at the back of the shelf
The twin flange mounting on these will take the forces that occur when a greater weight exerts a downward force away from the supported area and not only this they look great!
these are measured from the back wall mounting single flange to the furthermost point of fixing effectively supporting a whole 6 inch depth of shelf from 1.5" from the wall to 7.5" giving your shelf great stability
minimum shelf depth for this bracket would be just over 8 1/2" or 220mm