Kyle Petty Black Band Why Did Kyle Petty Have A Black Band Over The 45 On His Hat?

Why did Kyle Petty have a black band over the 45 on his hat? - kyle petty black band

I noticed that Kyle Petty had a black stripe on the number on the hat during Tradin 'Paint' and other times at the track this weekend. Does anyone see or hear, why was it? I have not seen before.