This is a beginner two ball basketball drill that works on developing ball control, and improving both hands at the same time. It is important for a player to be able to drive either direction with the basketball. Two ball drills will force the player to spend time working on their weak hand, because they are not able to transfer the ball over to their strong hand (since it already has a basketball).
The side windshield wipers 2 basketball dribbling drill can be done pretty much anywhere that there is a flat surface. So if you have limited gym space or only an empty garage, this is a great ball handling drill to use.