A 25 gauge would be the smallest. bigger the gauge number smaller the diameter if I'm not mistaken. I believe a 25 gauge is .51 mm
<span>The difference between obese people and thin people isn't the number of fat cells; it's the size of them. You don't make more fat cells the fatter you get; you have the same number of fat cells you had as an adolescent. The only difference is that the fat globules within each cell increase as you store more fat. By the way, muscles work the same way; you don't make more muscle cells; the muscle cells get larger.</span>
