Mechanical hand. All the fingers actively flex and extend at the metacarpo-phalangeal joints. The ring and little fingers are also articulated at the proximal inter-phalangeal joints. The index and middle fingers are fully faced with rubber while the ring and little fingers are only rubber faced at the tips. The thumb and fingers extend when there is a pull on the operating ('pull') cord which is attached to the lever on the front of the wrist. The thumb may be passively moved across the palm to oppose with either the index or middle finger. Made by Steeper, c.1939.