slin is NOT measured in mcg bro, mcg is microrams and that is a way IGF is sold.....slin is sold by the IU, or international unit, slin is U100 meaning there are 100 iu's insulin per cc or ml
What you want to get is U-100 insuilin needles and the insulin itself is 100 units per ML. I prefer the 1/2 CC U-100 needles. Makes it very easy to measure small dosages.
I agree with Natural, get some 1/2cc slin darts as its easier. Draw the amount you want a shoot it. If you draw up to the 5 on the slin pin you have 5ius ready to rock. thats why I just get the humalong pens, just turn the dial and pull the trigger