Layer Slider Nav Button Not Displaying Properly

Here’s a screenshot of the issue I’m having: http://www.uscost.com/wp-content/uploads/2013/11/icons-not-displaying.jpg The buttons on either side are supposed to be the “right” and “left” navigation arrow buttons, but I get this weird F045 instead.

Any thoughts as to what might be causing this?

URL is http://www.uscost.com/home