mine are the lower right with a single notch. Cardas makes these for Ayre with their own logo. the notch is to lift/secure cables if one so chooses to use these for that purpose - i do not.
per the dealer i bought them from, it doesn't matter which way they are oriented, just make sure that you are consistant with orientation, and place 2 of them under the heavier side of the component.
PACE