WARNING: This is a 4/3 mount lens designed for 4/3 mount cameras. It does not work with Micro 4/3 mount cameras unless using an adapter!
This is a standard 2x teleconverter, which doubles the effective focal length of your lens and reduces the aperture by 2 f-stops.
For those of you who haven’t used teleconverters, please be aware: “there is no free lunch”. You will get a longer focal length, but at the cost of a bit of sharpness. Teleconverters generally work well with professional grade f/2.8 telephoto lenses. They do not work well with consumer grade f/5.6 zooms.