Phil Bottom Bracket Retaining Rings, stainless steel
For British-threaded frames (English, American, Japanese, Taiwan, Chinese, just about everything except Italian and pre-1995 French).
Stainless steel. The Red one goes on the Right (drive) side.
You need at least one Phil tool to install, and two makes life dreamy.
British - Stainless Steel 1.370x24 tpi-RH&LH
Italian - Stainless Steel 36mm x 24 tpi
French - Stainless Steel 35mm x 1mm