(4) Original 69 Camaro ground straps. To give you an example of how easily these clean up. The shiny one was soaked overnight in white vinegar and dried. Or any light acid will do the trick. If you want to make them really shine... after soaking you can take the strap and and lightly brush it against a soft wire wheel. Then hit it with some clear and they look like new. Free. Just pick up the shipping.
