# Lead time storefront block The lead time calculation lives on the bill of materials; this is what actually puts it in front of a customer. A theme app extension block you place on the product page, same as any other Shopify app block. No theme code to write or maintain. It reads the same number the rest of Orderkraft uses, and updates when that number changes. ## Questions **Do I need a developer to add this?** No. It's a theme app extension block, added through the theme editor the same way you'd add any other Shopify app block.