This example taken directly from Google’s documentation.
<script type="application/ld+json">
{
  "@context": "http://schema.org/",
  "@type": "Product",
  "name": "Executive Anvil",
  "image": "http://www.example.com/anvil_executive.jpg",
  "description": "Sleeker than ACME's Classic Anvil, the Executive Anvil is perfect for the business traveler looking for something to drop from a height.",
  "mpn": "925872",
  "brand": {
    "@type": "Thing",
    "name": "ACME"
  },
  "aggregateRating": {
    "@type": "AggregateRating",
    "ratingValue": "4.4",
    "reviewCount": "89"
  },
  "offers": {
    "@type": "Offer",
    "priceCurrency": "USD",
    "price": "119.99",
    "priceValidUntil": "2020-11-05",
    "itemCondition": "http://schema.org/UsedCondition",
    "availability": "http://schema.org/InStock",
    "seller": {
      "@type": "Organization",
      "name": "Executive Objects"
    }
  }
}
</script>