Prothane's motor mount inserts are crafted out of polyurethane, a material much more durable than rubber that can handle intense weight, heat, and pressure. Designed to fill the voids built into your OE motor mounts, these inserts will drastically increase the power transfer efficiency from your engine to the wheels. Since the voids were initially put there to reduce NVH, it stands to reason that filling in those voids will have the opposite effect. Installing Prothane's motor mount inserts may increase your NVH, but the increase to overall performance is worth it to some drivers. To top it all off, Prothane's motor mount inserts are covered by a lifetime warranty handled in-house here at DST. Made in USA Complete kit includes 12 bushings for 4 door applications Black Urethane color identifies ensures an OE look Designed by true enthusiast engineers Tested both on and Off-Road UPC 636169194542 ASIN B006YG6CK6 Color Black Brand Name Prothane Manufacturer Prothane Model Number 13-512-BL Material Type Polyurethane (PU) Manufacturer Part Number 13-512-BL Global Trade Identification Number 00636169194542