OK just checked it out. First, it is fiberglass. Second, they are NOT RS splitter. They are techart repros. Below is the difference. The first pic shows the RS splitter side lip turned up going towards the wheel well like a light version of the GT2. The second pic show what the Hong Kong reproducers have of wich is a techart repro where the lower lip on the splitters are consistent on the bottom only.
below is the Tech Art splitters
Now, the ebay vendor also mixes these styles so you really don't know wich one you are getting.