327 (Brown)Large size bar (2 to 2.25 lbs est.) This is our most popular compound. This bar is best used on all softer metals Aluminum, Copper, magnesium, zinc, almost any non-ferrous metal. Best known for use on raw, sanded, or milled parts, great for removing lines and polishing to a good shiny (cut and color) finish. this is done Prior to using 130 pinks for a final (mirror) finish.