Anatomy of the Penis, the breakdown of the penis can be helpful to understand the science of the X4 Labs Penis Extender. 

Penis extenders work by stretching out the corpus cavernosum, and with traction (slight tension) a process known as cytokinesis. The penis stretcher when used consistently allow for permanent growth of the penis. The results can be as much as a 33 percent increase over your current size. 

The Corpus cavernosum is where the arteries are located that allow the penis to expand and increase in both size and girth when sexually aroused. The dorsal artery is the artery men most commonly see as the one thicker vein that delivers blood to the penis to remain in an erect state, and also helps determines how hard the reaction is. 

The Foreskin is the skin that covers the shaft, and also the glans, also known as the tip, or crown of the penis. In the case of circumcision the foreskin is either fully, or partially removed.

The reasons for this are typically for cultural, religious reasons, or the belief that a circumcised penis is more hygienically sound, however this is now under debate. The X4 Penis Extender’s support piece is made to allow both cut, and uncut men to successfully and naturally enhance their size.

Located in between the shaft is the urethra, which expels both urine and semen - in the case of adequate sexual stimulation. A narrow urethra is known as urethral stricture can also affect the chance of insemination, as the condition will limit the amount of sperm than can exit during orgasm. This lowers the chance of successful impregnation of your partner as well as the potential to cause pain during urination.

Peyronie’s disease is the build up of plaque in the arteries causing a curvature of the penis to a varying degree; Peyronie's disease however can be corrected with the X4 Penis Extender. A slight curvature may not pose a problem in terms of performance, but may cause lower self-esteem for the male. In extreme cases it can make sexual intercourse painful depending on the angle of the curve.