It is best to check the suction of your pump just incase it is to much for you and this allows you to adjust it the way you want to know how many times to press the buttons. You can basically adjust the pressure 3 different ways by using the + and - buttons to give you the sensation that you are wanting but be warned that it can hurt if to much pressure is applied to fast so it is best to go slowly. The clear tube allows you to watch your dick grow into the size you are wanting and it doesn't happen quickly it can take a few times although we all wish it did grow and stretch quickly.
If your pump decides to go crazy and start sucking away at your penis then there is a quick release button and you can do so by holding the - button.
Water based lube helps the ring go over your penis but if you want you can take the ring off and put it on your penis then put the machine on it which ever is easier for you.
It is rechargeable so you do not have to worry about batteries.
My husband likes it but sometimes dislikes it due to the motor sucks it to hard for him but everyone has a different experience depending on the penis size.