Kaoz, you are correct, the 10 mark on a 1cc 29g would be 100mcg (if the dosing is at 1000mcg/ml), and going halfway to it would be 50mcg. The part about going "halfway" threw everybody off. Since there are only 5 marks, each mark would be 20mcg increments so going in between the 2nd and 3rd mark would give you 50mcg.