Abstract: A hand exerciser device for fatigueless muscular exercising of a user's hand, arm and wrist, comprising: a first and a second spherical ball, each sized to fit inside the palm of a user's hand and surfaced for comfortable skin contact. A rigid connector tube interconnects the first and second balls by having its opposite end portions slidingly extending through a bore in the wall of each corresponding ball, wherein free rotational motion of the first and second ball members independently of one another is achieved. The intermediate section of the connector tube forms an accordion pleating, providing limited universal joint capability.