Direct answer: RS16080 is the free flow kit listed for the 2005 to 2016 RXP-X, RXT-X and GTX group, and the same listing also carries the number WR04027. It belongs to the earlier hull generation, not to the 260 or 300 family kits, so it is the entry a legacy boat is matched against.
The entry is written across a long year band, from 2005 to 2016, and it names the RXP-X, RXT-X and GTX together rather than one hull alone. Two numbers sit on it, RS16080 and WR04027, which is why a buyer can meet either one for the same part. The kit is a free flow section at the exhaust position, produced in-house like the rest of the free flow range.
The split that matters is generation. A 260 or 300 boat is on a later free flow number, and the Spark is on its own entries, so the legacy band is not a fallback for a newer hull. Where the boat falls inside the 2005 to 2016 band, RS16080 is the entry, and quoting either number on the listing reaches the same part. Give the model, the year and the engine, and the fitment line confirms the boat sits inside that band rather than after it.
