Basically, the RICG Responsive Images WordPress Plugin allows the browser to choose the best image from a list. This plugin works by including all available image sizes for each image upload. Whenever WordPress outputs the image through the media uploader, or whenever a featured image is generated, those sizes will be included in the image tag via the srcset attribute.
You can output a responsive image anywhere you’d like by using the following syntax (example):
RICG Responsive Images
<img src="myimg.png" <?php echo tevkori_get_src_sizes( 11, 'tevkoriMedium-img' ); ?> />