Products details page - when a product is viewed

<script>
var dataLayer  = window.dataLayer || [];
dataLayer.push({
  'ecommerce': {
    'detail': {
      'actionField': {'list': 'Phones'},    //List is optional
      'products': [{
        'name': 'iPhone 6',     //name or id required
        'id': 'ip22122',  //name or id required
        'price': '699.99',
        'brand': 'Apple',
        'category': 'phone',
        'variant': 'rose gold'
       }]
     }
   }
});
</script>