Adjustable Dumbbells - 24kg (Pair)Adjustable Dumbbells 24kg (Pair) The Fitness Hero adjustable dumbbells allow you to change your dumbbell weight load to suit exactly what you need, when you need it. You can customise the weight to suit which exercise and training styles you need in that moment. You can even change the weight between sets with the super easy dial at the end of each dumbbell. This means one set can now be responsible for all the resistance training in your workout.