Using Html.ActionLink to call action on different controller

I am trying to navigate between controllers using ActionLink. I will tell my problem with an example.

I am on Index view of Hat controller, and I am trying to use below code to create a link to Details action of Product controller.

<%= Html.ActionLink("Details", "Details", "Product", new { id=item.ID }) %>

Instead of creating a link to Details on Product controller, this generates a link to Details action under Hat controller and appends a Length parameter to the end of it:

Hat/Details/9?Length=7

I am not able to use HTML.ActionLink to switch between controllers because of this problem. I will appreciate if you can point me to what I am doing wrong. Thanks

PS: I am using the default route setting that comes with MVC

routes.MapRoute("Default", "{controller}/{action}/{id}", 
                     new { controller = "Home", action = "Index", id = "" } );