Help needed for extender

Hello guys . I plan to buy an extender and I wonder which one to purchase.
I see that there are types with tension springs and also some extenders don’t have tension springs which one is better ?
Also I see that there are extender with vacuum for the head and extenders with noose strap for the head which one is better ?

Also I search but didn’t find any thread about all general information for extenders ?

I mean with extender my main goal is to stretch more than my BPEL in order to gain ?

The best extender out there is the Pnimaster. It has it all with zero disadvantages.

The STRAP or the VAC is a matter of personal preference and they both have advantages and disatvantages.

And no … the main goal is not to stretch more than BPEL in order to gain…
The main goal is to extend at the TENSION in grams that is making your dick to grow.