PURPOSE: To make it possible to variously change grip training and to prevent the aging of the brains by connecting a pair of hollow elliptic balls made of a synthetic rubber sized to the extent of allowing light gripping with the palms to a rubber tube and sealing water and air corresponding to the amt. for one piece of the elliptic ball therein.

CONSTITUTION: A pair of the right and left hollow elliptic balls 1, 1 are connected by the rubber tube 2. These elliptic balls 1 are formed of the synthetic rubber material in such a manner that the balls have soft tennis ball-like elasticity and that the hand of the surfaces fits to the skin sensation of the palms and fingertips. The rubber tube 2 is formed of the synthetic rubber having the strength to withstand the atm. pressure and water pressure. The water and air are sealed into the hermetically sealed balls. A pair of the elliptic balls 1, 1 are deformed and the water and the air are moved while the elasticity determined by the amt. of the water and the air is exhibited when a user simultaneously grips the elliptic balls 1, 1 with the right and left palms. The palms and the fingers are moved by applying changes in intensity and speeds to the ways of gripping. The gripping by positioning the one elliptic ball 1 above and the other ball below is possible as well.