Before you create a product variation listing, check whether this variation of the product is already in the Amazon catalogue. If the variation exists and corresponds to the item you want to list, you can click Sell yours instead of creating a variation. If the variation does not exist, follow the procedure below to create a variation using the Add a Product tool. You can also view existing child ASIN(s) for parent ASINs in the Amazon catalogue on the Add a Product page in your seller account.