Quote from: markorock37 on March 04, 2024, 01:18:36 PMThere is some metal exposed on the back of these newer transistors. I think it will be best to use the insulators.Thanks for the update. Yes, you need the insulators. I was mistaken as far as the datasheet goes. I found pictures of other transistors with the same package (TO-247) and they are not insulated on the back either.