This exercise is great for lats. To perform it you will need an elastic band and a door or some other object. For example, you can make a knot in the middle of the band and place a knot behind the door and pull the door closed or you can simply tie the band around some object that is high enough.
Sit on the ground with your back straight. Grab elastic band in your hands.
Bring the elastic band to your sides. Make sure you are performing this exercise with lats and not with bac