Product Free Shipping can be setup to highlight the Free Shipping aspect of the product.
These pages include a Free Shipping Image on them.
You can define the ALWAYS_FREE_SHIPPING_ICON in the language file. This can be Text, Image, Text/Image Combo or nothing.
The weight does not matter on Always Free Shipping if you set Always Free Shipping to Yes.
Be sure to have the Free Shipping Module Turned on! Otherwise, if this is the only product in the cart, it will not be able to be shipped.
Notice that this is defined with a weight of 5lbs. But because of the Always Free Shipping being set to Y there will be no shipping charges for this product.
You do not have to use the Product Free Shipping product type just to use Always Free Shipping. But the reason you may want to do this is so that the layout of the Product Free Shipping product info page can be layout specifically for the Free Shipping aspect of the product.
This includes a READONLY attribute for Option Name: Shipping and Option Value: Free Shipping Included. READONLY attributes do not show on the options for the order.