What is the principle of hydraulic wrench without reaction arm? What do you mean Katko didn't respond? Can you explain the answer in detail?

This is a scam. Anyone who knows something about basic mechanics knows the basic principles of acting force and square acting force. He just put the tail arm of the original hydraulic wrench on the drive shaft. Decades ago, this design was used in pneumatic torque wrenches, electric torque wrenches and torque multipliers.

It's just that this seems novel to Katko Company, which has never been exposed to pneumatic torque wrenches, electric torque wrenches and torque multipliers before, and it's a big joke to talk about the arm without reaction force! ! ! ! ! ! !