Mellow Yellow in concentrate form.
Mellow Yellow wheel cleaner in concentrate form… so it's double the strength than the standard spray. Therefore, dilute it 1:1 with water to refill the Mellow Yellow spray bottle, or use it neat for refurbishing wheels and brush it on.
Remember that dilution ratios are just a guide, so you could even dilute it to weaker ratios than 1:1 to suit your application (say, if you clean the wheels regularly and they don't get very dirty between washes).
Remember that this is a strong acidic product and sensible precautions must be taken during use.