The 52mm Aperture Lamp is on the left, the 80mm is on the right.   Increasingly, round DE fog lamps are being mounted as Original Equipment and sold as part of aftermarket ground-effects. This is a small, 3 1/4" round, projector type fog lamp.   A Projector type lamp uses an ellipsoid reflector and a focusing lens to achieve high output in a small package.   DE Fog technology adds a shield to produce the sharp cutoff necessary for an effective Fog pattern.  

This lamp is used for the 1997-1999 Toyota Camry.   Please See Below.

This is the same lamp used on Mazda Miata although there are differences in the adjusting screw.   Modification is rquired.

The two upper mounts are the pivot points for vertical adjustment and the bottom mounting point is the adjusting screw.