Black powder coated steel.
JT and JL option are only available for halogen style tail lights and are not available for the LED style tail light w sensors.
YJ, TJ, and JK attach using stock hardware. JL and JT (halogen) attach using included double sided adhesive.
I've had these spider taillight covers on for two weeks and gotten dozens of compliments. They are heavy duty, will definitely protect the lights, and also have a great rough finish. Love them.
These people are awesome to work with. The item is great. High quality, heavy not cheap plastic. Came in right on time and as expected. My daughter is so happy with her tail lights! Would buy from them again.