This is an unopened, unused item, but the packaging has dust and grease stains. Please refrain from bidding if you are concerned about this. This listing is for a total of 6 pieces: 5 of 12mm and 1 of 10mm. I am not a specialist, so I cannot answer questions regarding usage. Please judge the product based on the images. No claims and no returns accepted. ◾️◾️No individual sales or combined shipping with other items listed◾️◾️ I cannot offer discounts. The price will be lowered if the item does not sell. I am also selling this item elsewhere, and the listing will be removed if it is purchased.