once you set your zero (say at 100 yards), you:
take the turret cap off
loosen 4 set screws and slide the stop until it touches
tighten set screws
put cap back on.
now your zero is as far down as it will go. if you dial up whether is 5 or 65 minutes, without looking, you can just turn your turret down until it stops and it will return to your zero.
I am sure no one else has done this, but on occasion i will get my gun ready to go shooting and I notice that it is dialed up. (was it one revolution, or three?) with the zero stop, just turn down until it stops and your good to go.
I think its worth every penny for sure.