The New EC Series comes in two sizes to fulfill different needs. According to our feedback from the players and our fans, ZOWIE had added the big mousefeet back to the EC Series. The Difference between EC and EC-B series, are mainly the mousefeet, which provide precise overall traction and tracking/gliding feeling. The ergonomic design exclusively for right-handed users. It offers users a bigger room for wrist movements. The shape of the right side of the mouse is well rounded. It allows the user’s fingertips to hold/cover the mouse to move smoothly.