This is a great looking sconce.  We installed them vertically on either side of our mirror.  If you are using a surface-mounted medicine cabinet be sure to measure how far it sticks out because you may not be able to see the lights from the side.  Other than that, it's beautiful.  Also, if you are using two, make sure they are hung in the same manner as one had to be adjusted after installation because one was leaning forward and the other was leaning back.