The factory LS1/LSx oil pressure sending unit is mounted directly behind the intake manifold, under the brake booster hose. When mounting an aftermarket 1/8 NPT oil pressure sending unit, there simply isn't enough room. In order to mount the sending unit in place of the factory sensor, the aftermarket unit must be angled to clear the factory intake manifold and brake booster hose. The HYBRID PERFORMANCE LS Oil Pressure Sending Unit Angle Mount Kit addresses this issue by allowing your aftermarket 1/8 NPT sensor to be mounted at a 45 degree angle for a clean installation.