Set the appropriate weight matching your fitness level and your type of training. Sit on the bench with your chest against the rest and press your feet against the floor. Grab the handles of the machine arms using an overhand grip with your arms outstretched forward.
From the starting position move your arms apart and backwards by contracting your back and shoulder muscles. When your arms are stretched apart your wrists are at the same level as your arms and chest. Your elbows are slightly flexed, keeping the same angle throughout the entire movement. Fix your body core to avoid lordotic swayback (over bending your back) at the waist when overcoming the resistance. Exhale when moving your arms backwards and inhale when stretching your arms forward.
Do not overestimate your abilities when choosing the weight. Make sure you keep your hands in the correct position and avoid excessive dorsal wrist flex. Avoid over bending at waist when overcoming the resistance. Your chest and your entire body core should stay firm and fixed throughout. Avoid involving the upper trapezius muscles. Exercise by pulling and make sure you do not use a jerky movement. Return to the starting position in a slow and controlled motion and avoid sudden relaxation of the muscle tension.
The number of repetitions depends on the type of your training.