Sold as a pair, these spring retainers allow easy movement of the standard OEM C2 shape spring to sit on the underside of the new top mounts. This can be the factory spring or an after market lowering spring.
For there to work, your Internal diameter of your spring should be 70mm.
I have included pictures of the top mount underside and one with the retainers fitted to the top mounts for understanding on how it is fitted or used. Note the top mount picture is upside down, the circlip should be facing downwards..