The ENGINEER ZC-28 neji-saurus liquid is a fast acting rust remover fluid. Simply dispense a small amount of fluid onto the rusty object (screws, bolts etc.) & Watch it work instantly (liquid turns Purple as it acts) -there's no need to scrub! The ZC-28 is a neutral liquid & therefore less harmful to bare skin compared to acid or alkali based products. Suitable for the removal of red, brown & Yellow coloured rust as found on Iron, stainless steel, brass & copper etc. (This Product is not suitable for white coloured rust (aluminium etc.), Black coloured rust (iron oxide) or green coloured rust (verdigris).