Abstract: A device for improving motion, extension and control of an arm of a person playing a game such as bowling comprising a band of flexible material having an inner surface which is in firm contact with the arm of the person in the area of the wrist and above the hand when the device is worn during use and having an oppositely-directed outer surface. A weight is fixedly held on the outer surface of the band and comprises a quantity of closely-packed metal pellets within a flexible container. A pair of loop-like elements are fixed in spaced relation to the band along one end thereof, and a pair of flexible straps extend in spaced-apart, generally parallel relation outwardly from the opposite end of the band. Each of the straps is provided with a fastener on the outer surface thereof, and a pair of mating fasteners is provided on the outer surface of the band.