• On a sticker or label located on the bottom or back of the product.
• In the product's user manual or warranty card.
• On the product's packaging box.
• In the settings or information section of the product (especially for digital appliances).
• On the manufacturer's website, specifically on the product detail page.

However, the location can vary slightly depending on the product, so it's always a good idea to refer to the product's user manual or the manufacturer's official website.