Current-facts boundary: 本页只发布本轮审核通过的当前事实。历史 JSW 页面可用于迁移背景，但不作为当前 RF 事实；现有 RF 强营销表述也未自动复制。
Reviewed Current Facts
- Official current public naming: RF420 街道小四活塞.
- Reviewed disc configuration: 330 mm / 355 mm; high-carbon or carbon-ceramic options.
- Current matrix pairs RF420 with street-formula pads and custom hose/bracket components.
- Current availability is inquiry-confirmed; this page does not promise stock or every vehicle fitment.
- RF420 is not RF420S or RF420SM.
Claim & Scope Limits
- No blanket DOT/CE/CCC claim.
- No claim that every component is manufactured in-house by JSW.
- No absolute NVH, fade-elimination or vehicle-level validation claim.