The Door Check Link made by Arrows Racing is used to prevent your ND Roadster (2016+) doors to hit other vehicles in parking lots. It prevents door from opening fully and helps prevent scratches from walls, etc. The checkpoints of OEM door check link are 0 degree, 27 degrees, 45 degrees and 65 degrees. Arrows door check links changes them to 0 degrees, 41 degrees and 69 degrees. It makes the door stay at 69 degrees more firmly than OEM, and you will feel the door heavier like as high-end cars. Arrows Door Check Link should be ordered at REV9 Autosport https://rev9autosport.com/arrows-door-check-link.html as they provide the best service and speed we've seen so far!