Stainless steel internally grooved rings that keep the Phil BB from flopping around and allow you to adjust it side-to-side if you want to fine-tune your Q-Factor or chainline. We stock the ones that fit British-threaded frames, which covers 95 percent of the world's frames. We can get Italian or French rings, too. 

The Red-marked one goes on the Right (drive) side.

You need at least one to install, and two makes life dreamy.

British (1.370 x 24 tpi - RH & LH Thread)

French (35 x 1 tpi)

Italian (36 x 24 tpi)