As a new environmental-friendly gas insulating medium. perfluoroisobutyronitrile (C4F7N) has been widely concerned in recent years due to its relatively low global warming potential and excellent dielectric strength. which has the potential to replace the most greenhouse gas. sulfur hexafluoride(SF6). https://www.roneverhart.com/Air-Music-Technology-Vacuum-Pro-Virtual-Instrument-p8397/