X20 EF20 Flash Difference

My guess is you want to know the difference between the EF-X20 flash ( http://fujifilm-x.com/accessories/en/flash/clip-on-flash/ef-x20/ ) and the older EF-20 Flash. The new flash has a number of things it can do that the older one can not do, but the price is higher and it can’t bounce. Also see this: http://www.fujixseries.com/discussion/89/fujifilm-ef-20-ef-42-shoe-mount-ttl-flashes/p1