Hiya KiddaMan,
Yes, these are set by the values given to your h2 style. If you just alter the h2 style though, it might impact on other areas of your site that have also been assigned the h2 tag.
So you should make a new rule just for the h2 tags within the gridBox class div on that page. So, in your: webassist/themes/Luxehats/css/default_styles.css stylesheet, at or near line 348, find:
.gridBox {
}
and just after it add a specific rule for h2 tags within the divs with the gridBox class:
.gridBox {
}
.gridBox h2 {
font-size:12px;
font-weight:bold;
}
You can play with the font-size and weight values until it is right for your design.