CanDo® Hand WaTE Balls are small and flexible enough to grasp with one hand, yet large enough to use for two-handed exercise. Balls increase in weight from 1.1 lbs. to 6.6 lbs. (0.5 to 4 kgs.) while maintaining a constant 5" (12.7 cm) diameter. Vary diameter slightly by inflating/deflating making ball harder/easier to grasp.