How to add custom field to custom post type?
===

Good morning.

I have created a custom post type called 'Products'. I want to create a custom field (is metabox
the correct term?) where my client can tick a box to determine whether a given post within this
CPT is a featured post.

Here is the code in my functions.php to create the 'Products' CPT:

    function products_custom_init() {
     
        $labels = array(
            'name' => _x('Products', 'post type general name'),
            'singular_name' => _x('Product', 'post type singular name'),
            'add_new' => _x('Add New', 'products'),
            'add_new_item' => __('Add New Product'),
            'edit_item' => __('Edit Product'),
            'new_item' => __('New Product'),
            'view_item' => __('View Product'),
            'search_items' => __('Search Products'),
            'not_found' =>  __('Nothing found'),
            'not_found_in_trash' => __('Nothing found in Trash'),
            'parent_item_colon' => ''
        );
     
        $args = array(
            'labels' => $labels,
            'public' => true,
            'publicly_queryable' => true,
            'show_ui' => true,
    		'show_in_menu' => true,
    		'show_in_nav_menus' => false,
            'query_var' => true,
            'rewrite' => array('slug','pages'),
            'capability_type' => 'post',
            'hierarchical' => true,
            'menu_position' => 5,
            'supports' => array('title','editor','thumbnail','excerpt',)
          );
     
        register_post_type( 'products' , $args );
    }
    add_action( 'init', 'products_custom_init' );

So how do I add the 'featured' metabox / custom field to *only* Products posts?

Many thanks,

Cynthia