How to make a picture flip button_html/css_WEB-ITnose

Image css

Please tell me how to make the flip button in the above image.
is to use a transparent image as the background. It is also implemented transparently with CSS.

Reply to discussion (solution)

.btn{width : xxpx;height : xxpx;opacity : 0.25; /* firefox  chrome等 */filter : alpha(opacity=25); /* IE支持 */}