Penis extension is used to increase the length and girth of your penis thus increasing the pleasure you give to your partner as well as giving her a totally different sensation. Penis extensions can also be used to sustain an erection. Just like a condom but made of a much thicker material extension is placed over the end of the penis. Made from realistic materials that adjust quickly to body temperature penis extensions feel just like a real penis. The major differences between extensions is the size. They range from 1.5 to 4 inches and some feature vibrating function.