Rubberized dumbbells Made from the best rubber and treated materials that are impervious to rust, breakage, and moisture, it has a soft texture that is appropriate for use by both men and women, and it has a comfortable grip that doesn't hurt their hands. The required weight is determined by adding the combined weight of both hands when filling the dumbbells in pairs (each hand is one piece). Dumbbells weighing 40 kg, for instance, indicate that 20 kg is carried by the right hand and 20 kg is carried by the left hand. Dumbbell advantages Dumbbells are vital and necessary for sports in general, whether or not they are used, to maintain physical fitness, get