We know of prosthetic 4-5s being used in movies to enhance the actors body parts and it seems like this trend has made it's way in to the real world.
A photo surfaced on twitter of what is called a "Dick print" that normally shows when men are wearing tracksuits and one user claimed to be selling them and even listed his contact numbers below.
The reason behind this was that if women can wear booty and make up, so they can also wear a 4-5 print. Prosthetic 4-5s have a history of being used to deceive as some of them are as good as the real thing.
According to Marie Claire, the needs for prosthetic penises can vary: Sometimes, actors understandably don't want millions of viewers to see what they look like fully naked. Sometimes, their characters are supposed to be packing a lot of heat. And sometimes, as in Daniel Radcliffe’s case, they have need for an on-screen erection that doubles as a compass.