It's just a simple way to mark the resistance, not to mention whether this measurement is accurate. 40kg, you open your hands, which means that you pull 20kg with one hand just to show the load. This kind of thing cannot be converted. For example, a bucket of water dispenser 19kg is 19kg. It is definitely more difficult for you to hold something than to pull it, because the angle of action is different, the direction of force is different, and the object itself is different. The puller gives you a handle to hold the bucket well,