From their site: Sandalistas are the first sandal perfectly designed for you.  To start, the footbed is anatomically shaped and contoured to match the human foot and eliminate pressure and friction.

Sandalistas are the first footwear with built-in Lynco support that incorporates the benefits of the world’s most successful foot orthotic system.  Instead of using firm materials, Sandalistas are made with IQ150 Memory Foam that conforms to your specific gait pattern and ensures an equal distribution of pressure while you walk.  And just in case all of this isn’t enough, patented Mozaic Customization Technology is built into the footbed to allow you to immediately customize each sandal so that it provides the ultimate in personalized comfort and performance.
 
Aetrex Sandalistas are available in four fashion-forward styles and in an attractive choice of colors.  We guarantee that Sandalistas will provide you with an extraordinary footwear experience.  Your feet will never look or feel the same!