add_filter('wcfm_marketplace_settings_fields_brand', function($fields) {
    global $WCFMmp;

    if (isset($fields['banner'])) {
        $store_banner_width     = isset( $WCFMmp->wcfmmp_marketplace_options['store_banner_width'] ) ? $WCFMmp->wcfmmp_marketplace_options['store_banner_width'] : '1650';
        $store_banner_height    = isset( $WCFMmp->wcfmmp_marketplace_options['store_banner_height'] ) ? $WCFMmp->wcfmmp_marketplace_options['store_banner_height'] : '350';
        $banner_desc_text = sprintf(
            __('Banner Image Dimensions: %1$s x %2$s pixels (width x height).', 'wc-frontend-manager'),
            $store_banner_width,
            $store_banner_height
        );

        $fields['banner']['desc'] = $banner_desc_text;
        $fields['banner']['desc_class'] = 'wcfm_page_options_desc';
    }

    if (isset($fields['mobile_banner'])) {
        $store_banner_mwidth    = isset( $WCFMmp->wcfmmp_marketplace_options['store_banner_mwidth'] ) ? $WCFMmp->wcfmmp_marketplace_options['store_banner_mwidth'] : '520';
        $store_banner_mheight   = isset( $WCFMmp->wcfmmp_marketplace_options['store_banner_mheight'] ) ? $WCFMmp->wcfmmp_marketplace_options['store_banner_mheight'] : '150';
        $mobile_banner_desc_text = sprintf(
            __('Mobile Banner Image Dimensions: %1$s x %2$s pixels (width x height).', 'wc-frontend-manager'),
            $store_banner_mwidth,
            $store_banner_mheight
        );
        $fields['mobile_banner']['desc'] = $mobile_banner_desc_text;
        $fields['mobile_banner']['desc_class'] = 'wcfm_page_options_desc';
    }

    return $fields;
});