Description
Replacement front gear case brass plug. This is used to plug the TOP sight glass window that ESS Tuning leaves in place, when they install a lower sight glass window when the rotor pack is flipped over. This prevents someone from accidently over-filling the supercharger to the very top window by accident. This is also used to delete the sight glass to prevent over-filling in custom applications.
It will also fit other applications, where someone may wish to plug the oil level sight glass, making it inoperable.

Ford Mustang/F150 5.0L Coyote 2.9L 175AXF Whipple Supercharger to Intercooler Mounting Base Plate
Whipple 1.6L 100AX extended drive supercharger head unit 