- 外: outside; external side
- 定位: fixed position; location; or ...
- 环: ring; hoop
- 外环，外定位环: outer ring
- 定位环: abutting collar; circlip; distance ring; holding ring; locating ring; register ring; registerring; set hoop; spacer ring
关注微信公众号：chachacidian，回复:外定位环，即可在微信中查询翻译
