Size not being displayed on productdetails page

I am doing CRUD using serializers and foreign keys and I have made a product details page which shows the details of the product that I have clicked. The problem is that the Size(SM,M,L,XL,XXL) itself isn’t coming but the id is coming as shown below

below is the ‘productdetails’ function

<tr>
    <td>{{data.id}}</td>
    <td>{{data.title}}</td>
    <td>{{data.price}}</td>
    <td>{{data.sku_number}}</td>
    <td>{{data.product_details}}</td>
    <td>{{data.size}}</td>
    <td>{{data.quantity}}</td>
    <td><img src="{{data.image}}" alt="product image" width="400" height="400"></td>
</tr>

productdetails function

def productdetails(request,id):
    prod = Products.objects.get(id=id)
    product = POLLSerializer(prod)
    return render(request,'polls/productdetails.html',{'data':product.data})

model

class Products(models.Model):
    categories = models.ForeignKey(Categories,on_delete=models.CASCADE)
    sub_categories = models.ForeignKey(SUBCategories,on_delete=models.CASCADE)
    color = models.ForeignKey(Colors,on_delete=models.CASCADE)
    size = models.ForeignKey(Size,on_delete=models.CASCADE)
    image = models.ImageField(upload_to = 'media/',width_field=None,height_field=None,null=True)
    title = models.CharField(max_length=70)
    price = models.CharField(max_length=10)
    sku_number = models.CharField(max_length=10)
    product_details = models.CharField(max_length=1000)
    quantity = models.IntegerField(default=0)
    isactive = models.BooleanField(default=True)

serializer

class POLLSerializer(serializers.ModelSerializer):
    class Meta:
        model = Products
        fields = "__all__"

size model and serializer

class Size(models.Model):
    size_name = models.CharField(max_length=10)
    size_description = models.CharField(max_length=20)
    isactive = models.BooleanField(default=True)

    def __str__(self):
        return self.size_name

class SizeSerializer(serializers.ModelSerializer):
    class Meta:
        model = Size
        fields = "__all__"