Direct answer: A generic kit is listed against a model name, while Intiracing lists rear exhaust for a Sea-Doo 300 by hull year and outlet layout, so the number on the listing states which boat the part was formed for.
The catalogue carries several 300 numbers because the hull changed under the same engine cover. RS15120 appears twice, as the 2022+ GTX RXT-X titanium kit and as the 2018-2021 RXT-X GTX 300 kit. RS16140-1 reads 2016-19 RXP-X 300 and 2016-17 RXT/GTX 300. WR04039, WR04066 and SEADOO-08 carry the later RXP-X, GTR 230 and RXT-X years. A generic kit for a Sea-Doo 300 rarely states that split, so the hull year is checked before ordering.
Material is the second difference. Intiracing names titanium in the title and treats a dual outlet as its own number, RS15120-D for the 2018+ RXT/GTX and RS15190-D for the 2021-2022+ RXP-X 300. A generic kit may leave the alloy and the joint method unstated, so the buyer compares a photo with a part rather than with a number.
