This lens is made for a Full Frame Sensor, but it is available in a M4/3 mount. Though, since it is an Ultra Wide, with some barrel distortion, it may not be an ideal choice, seeing the Panasonic G 14mm f/2.5 ASPH is made for the M4/3 sensor. But, it is an option.
If you’re interested in the Samyang 14mm (or whatever it’s called where you are) then consider what it is you want to use it for?
For some people the lack of AF and having to manually stop down the lens to the working aperture will be a show stopper.
However I found it perfectly easy to use out and about, by making use of good depth of field at f/8 and an ability to roughly estimate distances.