When purchasing levelers for any corner cabinet, make sure to add an EZ-Susan in the rear. This allows you to lift the far back corner with ease... and keep it from sagging.
The photo shows (1) EZ-Susan mounted to the bottom of a corner cabinet. The cabinet is upside down so that you can see the leveler.
With the EZ-Susan, we now level the Rear Corner first... then the other rear levelers. Then... simply adjust the front feet till they touch. NOW... leveling Susans usually takes less than a minute!
IMPORTANT NOTE:
The EZ-Susan comes with a 5" extension by default. (for deeper cabinets). It simply extends the adjusting rod and can be omitted during installation if not needed.
However... If you choose... and If you are sure the extension is unnecessary, you may opt out by choosing the "EZ-Susan ONLY" option, saving four bucks.