STARTING POSITION:
You need to find two pulleys together and place them at the highest level. Select the appropriate resistance in the weight stack. Place a flat bench in front of the pulleys. Grab a handles with each hand and sit on the bench. Use a supine grip. Contract your pelvic floor and core while keeping your chest up.
MOVEMENT:
Contracting your biceps, fully bend your elbows while you exhale. Make sure you only move the forearms. Return to the starting position in a smooth movement while you inhale. The moving weights should not touch the rest of the stack.
TIPS: The exercise key is quality over quantity. The trick is to perform the exercise using proper form.