A prosthesis for FTM is any device (packer, STP, Pack N Play, multipurpose, etc.) that can be worn semi-permanently with medical glue or harness. Prostheses can be more or less realistic and have a single function or more than one. The material must be hypoallergenic, generally silicone, or plastic materials. A very high degree of realism is preferred, with an uneven coloration of the prosthesis, veins, and realistic skin, preferably mobile. The use of medical glue is generally preferred, despite it entails more health risks, because it guarantees a more realistic result. Semi-permanent prostheses, worn with medical glue require a much more thorough hygienic care than prostheses used for short periods.