Hello,
the first product is the splitter itself, that can also be mounted without the carbon flaps.
The carbon flaps are just optional if you want them, some people here got it without the flaps and some others with the flaps, it depends on your personal taste.
You only need the carbon flaps if you wanna mount the big rear carbon ducktail spoiler, but if not they re as metioned above just an optional part.
Great, thanks for the explanation, all clear now 
So basically flaps are mounting on that splitter, so you can add them or remove them later .... if I dont like
Personally for me it's too much outside ... but I will look out for more pictures online to see and maybe to order just splitter for start....
Yes, I will use carbon ducktail spoiler also.
No problem bud!
Yes you can mount or remove them anytime.
But you have to be carefull, they are sold separately, so the price on the website is only for one flap.
But at least you will receive a great quality hand made carbon flap..
If you mount the carbon spoiler, due to legal reasons, you have to mount the flaps as well, otherweise its not legal.
Buuut i dont know how stuff works in your country, so, maybe its not necesarry and you dont need em.