As you can see in the picture below the hand has two fingers and a thumb. Each appendage is power by a RX-28. Which makes it too big for a Bioloid but the right size for research and for a human sized robot? The picture and the information about the hand is off of the Robotis support website. The path to the picture is: Home > 제품 설명서 > 로봇 플랫폼 > Robot Hand.