A man should prepare himself by masturbating or engaging in visual stimulation such that his penis is in a hardened state before having the machine attached to it.
Also, the penis may need to be lubricated; read the instructions see point 2 above to see if this is necessary and if a specific kind of lubricant is needed.
The chamber is pressurized and features a quick-release button in case you need it or when the workout is over.
The common thread is that all of them enjoyed the penis pumps.
Penis extender for cock stretching comes in different shape, size, and functionalities but then the basic design and principle of working are the same.
So the challenge with various manufacturers is to design a device that eliminates discomfort, pain, or any risk of injuries.
Some are manual, some run on batteries, some are water pumps for penis.
And some men find pleasure in imagining themselves an animal, such as a mighty bull, being relieved of his semen.