Position
Stand with your feet about shoulder-width apart. Lean forward, keeping your weight over your ankles. Maintain a natural arch in your lower back. Place your hands on top of the bar, about shoulder-width apart. Pull you elbows back, aligning your upper arms directly with the cable. Begin with your elbows pointed back and tight against the side of your body.

Technique
Slowly let the resistance pull your lower arms up and out in front of your body. Continue to let your lower arms come up to about a 90-degree angle, keeping your upper arms firmly in position. Hold, relax your hands, and contract your triceps. Maintaining your upper arms in position, slowly pull your lower arms back to their start position. Repeat.