This exercise is basic to work your triceps. At home, we use the resistance bands instead the cable machine.
Stand facing the cable machine. Position the cable attachment at a height above your head. Attach the handle or rope and grasp it firmly. Position your feet hip-width apart. Brace your abs to stabilize your spine. Keep your torso aligned and pull your shoulder blades back and down.
Exhale and straighten your elbows, pressing the handle/rope down toward the floor in a slow and controlled manner.
Continue pressing until your elbows are straight but not locked. Pause briefly.
Inhale and bend your elbows to start position. Stop the movement when the elbows begin to drift forward. Repeat.