The Morimoto Mini D2S 5.0: Is the best Bi-xenon projector for retrofitting headlights for more reasons than the fact that it's light output is superior. The ease of installation makes it even better, and all retrofitters know thathaving the right tools is key to a job well done. The Lock Ring: Itself is an anodized aluminum piece, made of CNC machined material. Versus the common die cast lock rings out there, this one is much stronger, and looks better. It also has grips to tighten by hand, and of course, slots to tighten using the lock ring tool --also available here. Lock Ring Tool: This tool is designed to apply more than enough twist to your lock rings when you're finally ready to clamp down and finish your retrofit. It is compatible with all 10mm socket wrenches, and of course Morimoto's blue anodized D2S 5.0 lock rings. Be Careful: This tool will allow you to tighten the lock ring so much that you can break your headlight reflector in half or crack it. Use a sensible amount of force, and finish the job with some JB weld to ensure nothing ever vibrates itself loose in the long run. Now get to work!