Woocommerce with metabox plugin

Here’s the metabox code what I’m using which is working fine for me:

// Add meta boxes with TinyMCE via wp_editor() function

// Define the custom box
add_action( 'add_meta_boxes', 'product_details_add' );                                                      
// Do something with the data entered
add_action( 'save_post', 'product_details_save' );
// Adds a box to the main column on the Product post_type edit screens
function product_details_add() {
    add_meta_box( 'product_details', 'Product Details', 'product_details_call', 'product', 'normal', 'high' );
}
// Prints the box content
function product_details_call( $post ) {
    // Use nonce for verification
    wp_nonce_field( plugin_basename( __FILE__ ), 'product_details_noncename' ); 
    $field_value = get_post_meta( $post->ID, 'product_details_meta', false );
    wp_editor( $field_value[0], 'product_details_meta' );
}
// When the post is saved, saves our custom data
function product_details_save( $post_id ) {  
    // verify if this is an auto save routine. 
    // If it is our form has not been submitted, so we dont want to do anything
    if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) 
            return;
    // verify this came from the our screen and with proper authorization,
    // because save_post can be triggered at other times
    if ( ( isset ( $_POST['product_details_noncename'] ) ) && ( ! wp_verify_nonce( $_POST['product_details_noncename'], plugin_basename( __FILE__ ) ) ) )
            return;
    // Check permissions
    if ( ( isset ( $_POST['post_type'] ) ) && ( 'page' == $_POST['post_type'] )  ) {
        if ( ! current_user_can( 'edit_page', $post_id ) ) {
            return;
        }       
    }
    else {
        if ( ! current_user_can( 'edit_post', $post_id ) ) {
            return;
        }
    }
    // OK, we're authenticated: we need to find and save the data
    if ( isset ( $_POST['product_details_meta'] ) ) {
        update_post_meta( $post_id, 'product_details_meta', $_POST['product_details_meta'] );
    }   
}

////////////

However, get_post_meta() is not returning the data in my template pages so I’m using a more “direct” method to get show the meta content:

<?php echo $product->product_custom_fields['product_details_meta'][0];?>

Of course this assumes that you also declare global $product; somewhere above this code in your template file.