The Cusco rear pillowball upper mount is a non-adjustable unit made for Subaru Legacy BP5 applications and specifically notes use only with ID65 springs. It provides a pillowball-style upper mounting option for the rear suspension of the Legacy BP5, and the listing explicitly requires pairing with ID65 springs rather than standard or unrelated spring setups.
Cusco Subaru Legacy BP5 Non-Adj Rear Pillowball Upper Mount (For Use ONLY w/ ID65 Springs)