Angelguoguo Aluminium Alloy Car Ignition Startup Switch Decoration Ring Cover Sticker for Mercedes Benz GLK/GLA/CLA/2015-2016 C Class (Red) Easy to install, there is 3M glue inside, you can DIY Give your Car Ignition switch the best protection and also looks very cool The materials is Aluminium Alloy, durable,and doesn't damage the car Fit for Mercedes Benz GLK/GLA/CLA/2015-2016 C Class Outer diameter is 0.159", inner diameter is 0.085"(please check the picture)