Low poly Robot Hand, FULL version. The light version is the item number 746950. The obj version is the item number 738039.
The hand is rigged and you have the control of every joint of the fingers and wrist, some parts are locked in some directions to prevent unacceptable moves, but its easy to unlocked them in settings. The rig permits also to control every single flip of the fingers, front and back, so you can open completely the hand and show the inside. In the wrist control there are fist and spread controls, and the master control of the arm can be parented to a potential forearm.
Number of joints: 54
If you don't need to show the inside you can check the light version.
The textures are all PNG 4096x4096: diffuse.png specular.png normal.png reflection.png
I've also uploaded the environment picture and the scene files that I've used to render the hand in mentalray.