The Subaru SVX engine uses 2 different crank angle sensors, and they're no longer available new. This adapter allows you to retrofit an EJ crank angle sensor. The EJ sensors use the same connector and signal as the SVX sensor, but the mounting point does not line up. You want to make sure that sensor is securely mounted in place, which is where this adapter comes in.
 
Due to the high temperatures the engine bay sees, these adapters are printed out of Nylon that are annealed to provide maximum temperature resistance. 

You will need a longer (M6x20mm) bolt to accomodate the thickness of the adapter which is not included. When installing, do not overtighten as the plastic will distort or break, and there is no need to have it super tight, only snug.