Forearm exercises you can do with a dumbbell set.
Sit and grasp dumbbells with narrow to shoulder width underhand grip (palms down). Rest forearms on thighs with wrists just beyond knees holding dumbbells. (You can also rest forearms over bench as an alternative) In a controlled motion, curl wrists up toward forearms. Contract forearms fully, without compromising form. While maintaining the controlled motion, return dumbbells to starting position. Do not allow muscles to relax before next repetition.
Sit and grasp dumbbells with narrow to shoulder width overhand grip (palms up). Rest forearms on thighs with wrists just beyond knees holding dumbbells. (You can also rest forearms over bench as an alternative) In a controlled motion, curl wrists up toward forearms. Contract forearms fully, without compromising form. While maintaining the controlled motion, return dumbbells to starting position. Do not allow muscles to relax before next repetition.