it is like a filler only used to cover scratch marks in depth not suited for gaps. Quite worth it if you go for metal finsh looks. Comes in liquid and spray form , made from gunze as you know. it can be substituted if you have a good selection of polishing cloths (1.2K , 2K, up to 10K) Quite worth it though it costs about 6 dollars in greece. guess more or less the same in the us