The manual states "Your air pistol is designed with an adjustment to change the trigger pull from 1 to 4 lbs." Unfortunately the language is misleading. Most, if not all guns will not be able to go down to one pound. The manual should state between 1 to 4 lbs. I think 2.5 pounds is the most realistic number.
*Note: This will be corrected in the manual when it is updated.