film arena is the name of the retailer, so whenever you see fa, it is simply the company, they sell regular Czech Steelbooks, Blu-rays and other items as well...including the FAC(film arena Collection - Numbered Edition)
FAC is their line for their ''collectible fullslips numbered items'' that are name FAC as Short for: film arena Collection = FAC
So what is sought after are those Film Arena Collection line which are numbered, they do vary in the numbering as well as some packages having WEA Steelbooks or simply using the WWA Steel as they do often, like ''The Martian film arena Collection - Numbered Edition'' for Short ''The Martian FAC'', it comes with a Stunning WEA Fullslips, for this release they used the WWA Steel, Most Often a Lenticular Magnet 3rd Generation most of the time with flip flop effect which are so nice(or at times simply 3D) and Bonus Items(Character Cards + other items as seen in the picture in the OP provided by film arena)... if you look in the OP that is called ''The Beautyshot''.
So for every FAC release (numbered edition) they will provide a ''Beautyshot'' as per the OP one and you can see all that will be included in the Package. When participating with the group Buy, they are more affordable and when you love the Package, when you receive your copy from Karel, you can see how stunning they make their FAC which are part of a collection Line...
They are Fullslips Numbered Packages worthy of owning... once you will have open your first FAC, you will see first that the quality of the WEA Fullslip is very lush and all items within this Fullslip make it what we all love so well, but just having the Fullslip in hands already you can see they are very nice quality little packages... So to make a long Story Short it is an Exclusive Fullslip Package that is made by the company ''film arena'' (..similar as exclusive Fullslips made by Nova, Kimchi etc..)...but they go like cup cakes... so whenever you are interested in a release, subscribe to the thread and check your alert as when the Gb opens sometimes it can fill up in a few hours other larger titles can be days you never know how long it will be...
Hope this help if you need more info don't hesitate.
...always happy to help 
