Motorcycle engine piston rings kit with 100mm diameter and part number 420890385.Compatible with RXP X 300 (2016–2022), RXP 300 (2016–2020), RXT 300 (2016–2020), RXT X 300 (2021–2023), 300 (2016–2022), LIMITED 300 (2021–2024), STD 300 (2023), 300 STD variants (2024–2025), GTR 300 X variants (2024–2025).Fits models equipped with 300cc engine.Constructed from aluminum.ring features nitriding treatment.Second ring is made of nodular cast iron.Oil ring is a wavy design.Scraper ring has chromium coating.Designed to restore fit and function. This is a non-OEM replacement.Any mention of brand names is strictly for compatibility clarification.