Image Number 5 for United States Patent #7077786.
A rotor is rotatably received in a casing to form a wrist exerciser. The rotor includes a spherical body defining a bore in which an inner flange is formed. First and second weight members are received in the bore on opposite sides of the flange. The weight members have inner end portions releasably attached to opposite surfaces of the flange. Through holes are defined in the first and second weight members to receive an axle of which ends project beyond opposite ends of the body to rotatably engage a support ring of the casing.