This strike is the opposite of the upward rollover. The strike moves from an upward position to a downward position. This strike can be independent or in combination with the upward rollover or added to other strikes.
As the strike moves downward, the body and hips drop down with the strike. Remember to keep your elbows and hands.
Your offhand should be moving up to protect your face. The rotation of the strike uses the elbow as the pivot point. As the strike reaches the target, you want your arm to be fully extended, but you want to keep your elbow unlocked to prevent from hyperextending your elbow.