This is a Speed/Reference sensor for a Porsche 944. It's made to be .8 longer than an actual sensor so you can properly Gap the sensor without gluing a washer to the end of it. To use, remove the sensors (not as easy as it sounds. My best shot was to remove the starter under the car and use a long 3/8s extension, a medium extension, a U-joint, then a short extension to loosen the bracket) Place this tool against the flywheel through the bracket hole, tighten the tool down to the bracket, then rotate the the bracket along it's axis until the tool hits the flywheel. Once that's been accomplished, tighten the bracket down, remove the tool, install the real sensor and your car should start! I hope this helped you fix your 944. I know there is someone who is trying to sell something similar to this with less accuracy for 30 so I've been told.