Locate the hex nut on the hinge end. The hex nuts on SA and SA1 provide different features. Make sure you adjust the correct hinge.   

➤ Use 5mm hex wrench to adjust the speed

➤ Turn hex nut clockwise ( – ) to lower closing speed; turn hex nut counter clockwise ( + ) to increase closing speed.

➤ Use 3mm hex wrench to lock your desired speed setting

NOTE:  The hex nut will screw into the barrel as you reduce speed.  Conversely, the hex nut will come out as closing speed increases.  The door will stop altogether when the hex nut is tightened all the way.