You are supposed to wear ProExtender System in the flaccid/semi-flaccid(normal) position of the penis.
You should NOT wear the device in the erect position. Why? Because your penis can be only stretched when it is in the flaccid(normal) position and it is in the flaccid state most of the time.
Hence it is recommended that you wear the device only when the penis is in the flaccid(normal) position.
To view the demo video, kindly visit: http://www.proextenderindia.com/demo