I found one of my replies in an other thread and it covers your question and a lot more.
Here is a copy/paste
""""""""Start very slow… and build up the volume. starting with 1h per day and add 1 more hour every 7 to 10 days.
Good and bad Pis are also applied in an extender therapy.
Extenders manufactures and some ppl think that the more hours the more gains… but the truth is a lot different.The dick can get overtrained with an extender as with any kind of PE exercise.
If your dick at a certain condition point can take 3h of extending and the Pis are great…but when you add 1 more h and the Pis are going shitty… then you will not gain much and you may not gain anything.(happened to me too)
You have to follow your good Pis and adjust accordingly.
Start with 2on/1off frequency and later on if u have good Pis go to 3on/1off-2on/1off . Stay there for some weeks and if you still have good Pis go to 3on/1on.
The 3on/1off frequency means that you are taking 1-2 rest days in the week. Yes extending also needs rest days.
Make sure ALL of your extending journey is super comfy… IF you find yourself at some point struggling from discomfort in order to reach your daily vol goal… then either you are using bigger intensity than u should…either bigger Vol than u should….either both. This is NOT good.
After every session your dick have to be longer-thicker-softer than your original size.
If your dick after the sessions is becoming turtled… back it up imediately!
Every dick is different in the matter of stress that is able to take and maintain good Pis.
Work your way to get conditioned first.
In the begining you may need to do 30 mins sets, in order for the glans to be conditioned under hypoxia (lack of oxygen from being strapped).
Latter on you will be able to do 90 mins sets… but you have to work slowly to get there.
Take at least 30 mins break between your sets.
Do not care to reach a certain total hour of wearing time (like 1000h).
Care everyday to be productive (good Pis) and not counter(bad Pis).
I did 260h in 400-600 grams 4/day 5days/week and I gained 0,5cm EL.
Then I upped the tension and the vol and for the next 1100h I gained nothing. I wasted 1 year without gains simply because I was not paying attention to my Pis.
At the 260h perfect Pis… Huge-soft flaccid with increadible libido and EQ and the gains happened in the EL.
At the next 1100h all of Pis went down and zero EL gains.
Well I did my part and posted you everything I learned from my extender journey. Now its up to you""""""""""
This is the Thread. Read it all
Extender Basics
Next time if you have any question use the SEARCH and if you will not find any answer then ask and if we know the answer we will help you.