Cable crossovers work the chest. The movement itself is more of a shaping exercise for the chest, which can be used in conjunction with power exercises, like the flat and incline bench press.
The cable crossover exercise is easier on your shoulder and elbow joints than using dumbbells or barbells. You also have more flexibility to move and position yourself. Start by grabbing both handles, centering yourself in the middle of the unit. Place one foot slightly forward, keeping your upper body parallel to the upper part of the unit. Bend slightly at the waist.
Keep your front knee bent slightly and rear knee locked for better leverage. Slowly pull both cables in front of the lower part of your chest, crossing both arms slightly. Get a good squeeze and exhale as you do. Inhale as you return the cables to the starting position. Do three sets of 10 repetitions.