Machined from 7075-T651 aluminum , then hard anodized . This Fast Forward manufactured LD 200 / MK diff is made with smooth rounded surfaces for less drag . And a large bearing spigot radius for strength. This differential weighs over 3 pounds LESS than the OE steel diff. It comes with bearings and cross pin. Your flat side gears and spider gears can be swapped over from you old steel diff.