If you have current auctions on eBay, the Injector will easily and quickly add the calculator to the bottom of your listing descriptions using eBay's 'Edit Description' process. (eBay policies prohibit modification for auctions which already have bids or which are closing within 12 hours). If you like using the Injector, you can use it for all your auctions by listing your auctions first and then using the injector afterwards.