A high quality penis extender usually has a medical sertificate to prove that the device is not harmful. It is very not recommended to buy a random penis extender online because chances are you won’t know if the product is safe, you won’t know how to use it correctly, and you won’t get complete package, and more importantly the product is not registered by the ministry of health so you won’t be able to sue them if something bad happen to you. You should always find a mentor while exercising because using penis stretcher is like exercising. There are many things you don’t know about exercising that will injure you instead, but your mentor knows.