These are a close up of the foot pedal arm. The roller is a earth magnet. I helps keeps hold of the pedal the pedal and is a nice smooth action by rolling on the pedal under acceleration. We all love acceleration to be smooth. Just a little side bar. Thank you guys for the kind words. This is probably my last build. I've been doing cars over 50 years. I will take some time and enjoys this one. Thanks again.