In Jeet Kune Do and Wing Chun a Lop Sao," or the "pulling hand," is a technique used to control an opponent's arm and create an opening for a follow-up attack. The practitioner quickly grabs or pulls the opponent's arm, disrupting their guard and balance. This allows for a strike with the other hand to vulnerable areas like the head or torso. Maintaining control of the opponent's arm after the initial attack helps continue the offensive or transition into another technique. Lop Sao emphasizes speed, precision, and disrupting the opponent's balance, which is great for attribute development.