Inserts into the subframe mounting holes to fill the 2mm gap around the bolts to provide a tighter fit. Prevents subframe from moving and rattling under load. Reduces wobble of the steering wheels with uneven pavement. Sharpens suspension feel and increases chassis rigidity. Rigid Collars are made from a proprietary alloy that has been rigorously tested under endurance racing and street driving conditions. The material has been specially formulated to slightly crush and conform to mating surfaces for maximum contact but not soft enough to break or deform under load or so hard the two surfaces simply slide against each other. Included in each kit is also a tube of specially formulated grease to prevent galling between the different metal compounds and to ensure proper installation. Spoon Sports holds US and international patents to protect this technology. Counterfeit products don’t have these properties and are produced using “off the shelf” materials with lower tolerances and without proper testing so they will not achieve the same results.