I had the Omnitrope Pen 10 which used a 10mg/1.5 ml cartrige that is one unit, no mixing required. I lost the pen and now need to figure out if im going to use a insulin syringe at the correct doseage. I have read and searched the site for two days trying to make sure but still not sure i have this right. Got even more confused when reading about mixing the water as Mine didnt require any mixing. Not sure why i cant figure this out... I was using 1.0mg or 3iu on my omnipen daily and need to know about the slin pen. Thanks in advance