My opinions...take them how you will...I seem to understand English is a second language for you.....
Extenders are good for a
total newbie with less time available. Newbies usually gain from
ANY METHOD in the beginning....that first, inch or so in length, and/or girth.
"Time available" is usually directly tied to
DESIRE....that's usually directly tied to
BELIEF in PE when new to it. Most men
LACK belief any method works in the beginning....
.lack of belief leads to lack of motivation and either not getting started, or not staying consistent.
All similar to physical fitness. Of course, the fitness industry is FULL of examples of different workout routines and "diets" working.
This industry, SO FAR, is NOT. It's mostly anecdotal "testimonials" and questionable at best pictures.
I think rather than buy an extender....you should find a good stretching routine....or even get into
weight hanging....which I find easier to stick with because you know exactly what resistance you are using every time rather than guessing when you stretch with your hands.....of course, that is an individual choice.