Sonax Wheel Cleaner Plus is a brand new, thicker, acid-free, pH balanced formula wheel cleaner that is safe for all types of wheels. The Plus formula is 30% stronger than the Sonax Full Effect. This is the perfect wheel cleaner for the dirtier, difficult to clean wheels. Sprays on fluorescent green and then turns red as it reacts with the iron particulates in brake dust making it easier to remove. The sintered iron particulates in brake dust are one of the more difficult components to remove from your wheels. This new formula attaches to the sintered iron particles creating a water soluble iron complex that allows the surfactants to rinse off easily. The new thicker formula will cling better to vertical surfaces better than the original formula. Perfectly safe for all types of wheels when not used in direct sun or on a hot wheel. Spray on a cool, dry wheel, spong evenly over the entire wheel surface to remove any drips or runs, allow it to work 3 to 5 minutes and then rinse off all traces with lots of clean water. Heavy accumulations of brake dust residue may require gentle scrubbing with a soft wheel brush or Blu-Velvet Microfiber Wheel Cleaner Sponge before rinsing and/or multiple cleanings.