TRD limited Slip Differential. Used but in good overall condition. Also comes with brand new bearings which are long discontinued and almost impossible to find. Not sure on the type of LSD this is. Although I’m fairly sure it could be mechanical. I believe it fits most C series Toyota gearboxes but I have also heard of them fitting in custom applications so I’m sure the world is your oyster if you know what you’re doing. It came into my possession as a package deal when I bought my 4age engine and gearbox.