This 500 Grams of Grade 600 Silicon Carbide is for the Third stage of tumble Polishing in a Rotary Tumbling Machine. Add four heaped teaspoons in a 3 lb barrels add water to just under the level of the stones and seal the lid and run on your machine for 1 week. DO NOT THROW ANY WASTE FROM YOUR TUMBLER MACHINE DOWN YOUR DRAINS,  AS IT WILL INTIME SET LIKE CONCRETE AND YOU WILL HAVE TO HAVE NEW DRAINS LAID. Pour onto the garden and hoe in any minerals will help in the soil. If you have any questions please ask as I am only too happy to reply to you. Thank you for looking. This grit is the same that I use in all of my machines.The cost of this item is £14.75 plus £3.00 P&P making a total of £17.75 including P&P.