How to POST JSON data from fiddler to api Controller in .net

See more:

ASP.NET

I have a model class Product as:

public class Product
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public string Category { get; set; }
        public decimal Price { get; set; }
    }

and the API controller is ProductsController and the Post method is:

 [HttpPost]
public HttpResponseMessage PostProduct(Product item)
{
    if (item == null)
        return new HttpResponseMessage(HttpStatusCode.BadRequest);

    item = repository.Add(item);
    var response = Request.CreateResponse<Product>(HttpStatusCode.Created, item);

    string uri = Url.Link("DefaultApi", new { id = item.Id });
    response.Headers.Location = new Uri(uri);
    return response;
}

When I post JSON data from fiddler Product item, I get null value, but get method works fine.
Please anyone help me to solve this problem.