The SMP Enlarger increases both penis length and girth by using traction, from its spring loaded steel rods, to assist the body's natural ability to change and develop under physical influence. If you subject the penis to constant stretching the cells will begin to divide and multiply, thus increasing tissue mass. This is a similar technique that African tribes have been using for years to enlarge their ears and lips. Note: The standard rods give a top length of 5 inches. If you wish for more extension, add the extension rods which can extend the top length to 7.5 inches.