Penis pumps look like cylinder-shaped hollow tube, which was designed to make man's erection hard. There are several ways to take advantage of penis pump: you may use it to create stronger erection or you may imitate oral sex with the help of this sex toy. Though your penis enlarges to a considerable degree, the effect is quite temporary. Due to the bulb available, penis pump works like a vacuum, where your penis elongated with the contractions of the air. This intense stimulation of penis pump makes your sensations very enjoyable.