3M inspection spray is used to inspect automotive surfaces for lingering sand scratches after buffing. The gallon of inspection spray contained within this can helps operators detect sand scratches and other defects that may otherwise not be readily seen. It does not harm paint or leave residue. When it comes to inspecting vehicles for scratches and marks, you can't risk unseen sand scratches. We engineered 3M inspection spray to help technicians locate these scratches even in difficult lighting conditions. This automotive inspection spray is specially made to reveal swirl marks and sand scratches after buffing. We recommend using 3M inspection spray after every buffing step to ensure that tiny imperfections are revealed. 3M recommends using this product with the 3M PPS, sun GUN, II light kit PN 16550. The easy to use inspection spray will not harm the paint or leave residue.