Example

HTML
<img srcset="images/AlleySpringMillsmall.jpg 400w, images/AlleySpringMillmedium.jpg 800w, images/AlleySpringMilllarge.jpg 1600w" sizes="(min-width: 400px) 100vw, (min-width: 800px) 100vw, (min-width: 1600px) 100vw"
src="images/AlleySpringMillsmall.jpg" alt="Alley Spring Mill">