This move, the Dumbbell Preacher Curl Over Exercise Ball, is a curl variation using a dumbbell. This curl variation is set up to minimize swing, so the biceps does the lifting instead of momentum. It's commonly used to correct strength imbalances between the left and right side.
Log your dumbbell preacher curl over exercise ball sets in 1RM.fit and watch your estimated 1RM update automatically as you get stronger.