BE CAREFUL. Too much vacuum will damage your penis, which I know from personal experience. When in my mid 30s, I bought an expensive pump. I was half an inch away from a glorious length. The pump quickly brought me to it. In addition, gym-shower softie was impressive. Sadly, it also weakened my ability to sustain an erection. I assumed that it was due to getting older, not the pump. One day, I noticed discoloration of my penis due to pumping, and I threw away the pump. About five years later, my penis had healed itself entirely but it was back to its original size. Many penis-enlargement exercises suffer from the same liability of damage to penis functioning.
The best (i.e. safest) pumps strictly limit the maximum amount of vacuum that can be applied, for example the bathmate products.
Some men in Hollywood get bicep implants that make them look buffed, but they cannot lift a bag of cement. The question is: Do you want an impressive looking penis or a well-functioning penis.