What is the difference between the Edge and Zen cups? Does one provide more suction than the other?

Our EDGE cups are made with platinum medical grade silicone which is also thinner and very transparent (preferred choice by massage therapists and other healthcare providers).EDGE cups create vacuum suction when you compress the cup at the top by pushing in the center; or you can squeeze the cup on both sides at the top. ZEN cups are made with thicker food grade silicone and are compressed from the sides with one hand. Both cups are great and are just a matter of preference.