Micro G Threaded Herbal Tank Replacement Micro G Herbal Coil Use with dry blends The microG Herbal Coil is a replacement coil for the microG herbal vaporizer. It is made with the new Grenco tank threading design. You can now easily thread just the heating coil directly to the battery. These microG Herbal Coils are compatible with the 2014 microG Vaporizer and the microG Herbal Kit. It is intended for use with dry blends. *Not intended for use with concentrates and essential oils*Durability index of microG Herbal Tank is approximately 5-6 weeks.