Penis enlargement procedures (sometimes euphemistically referred to as male enhancement procedures in spam email and television advertisements) are techniques alleged to make the human penis increase in girth, length, or hardness. Often, in the course of advertising fraudulent products, the distinction between temporary enlargement, i.e. erection, and permanent enlargement, is deliberately muddied. Procedures range from manual exercises to stretching devices and surgical procedures, with reports of successes and failures around the world. While some of these are known to be outright hoaxes, other techniques have some measure of success.