This is a GT series turbo oil drain fitting. This fitting allows you to build custom oil lines to your new turbo setup. Works perfectly with the Garrett GT-Series gasket. Every detail has been considered, the machining is very high quality.
This fitting has bolt holes that are 1.5 inches (on-center) from each other. If you have a Precision "GT" turbo, please confirm with them, that the drain is actually a GT-series bolt pattern drain. Unless you have actually purchased your turbo directly from Garrett, chances are your turbo has a "T-series" drain, the mounting holes are 2.00 inches (on-center).