Doctors use a device called an orchidometer to measure testicle volume. All they do is find the closest matching bead. It's simple as that. When a boy reaches size 4 (i.e. 4ml), then he is in stage 2 of puberty. You can still measure your testicle volume without your own orchidometer. I've included a simple printout version. The numbers in the ovals are in milliliters. After printing it out, make sure that the scale on the lower right matches up with 1 inch (measured between the black lines of the scale) on your ruler or you're wasting your time. The length and width of the largest oval are 1 7/8" and 1 3/16" respectively (including the black lines this time). When measuring your balls with a ruler make sure to push away the skin of your scrotum. Pull it as tight as you can. To my pleasant surprise I am 2 1/8" x 1 1/4" (the empty white oval I printed out). The reason I bring all this up is because I want to stimulate some fresh discussion on ways to increase testicle size. I have a 2-stage cylinder, but I use it infrequently. Has anybody had success enlarging their testicles? If so, what did you do?