How do you adjust an electric dog collar?

My mother has recently bought an electric dog collar home and i have been skeptical at best whether to put it on my dog. I have a very small dog, so i figured what way better than to test it on myself first before my poor thing. I was told it has 7 settings...to me it seemed to have just 1, and it entailed alot of pain, more than a dog should experience. It is a simple enough collar working on the vibration of sound, and I am not sure how to turn the intensity down. Please help! I dont want to hurt my dog and I refuse to put it on my dog until the intensity is bearable for me.