Hi Jonyoung,
Yes they worth the try, especially for length.
Extenders don\'t increase penis
Girth.
You can find all the informations you need on thundersplace.com, begin with the newbie routine, you won\'t need any material. Then buy material if you need it.
Start light and see what you can handle before increasing intensity, watch the impact on your
Erection quality etc., it\'s possible to injure yourself if going too strong.