Good used rear Limited Slip differential that fits the common Subaru R160 differential. R160 differentials are found in early 2000 model cars through 2015 depending on model but are normally equipped with an open differential. This is a common upgrade for 2008+ Subaru WRX to help both rear tires find traction especially in low traction conditions. This is a limited slip differential that is designed to increase the traction of your vehicle in various conditions such as snow, Ice, Gravel, Rain as well as track driving conditions by driving power to both rear tires not just the one that is spinning.