Customizing title for Related Products

Site URL: http://www.coindisplays.com

I have enabled related products on my site.  When a customer goes to one of our products, they see the related products at the bottom.  I was able to stylize some things like the amount of products shown and few other details however the title has been an issue.

Currently, it seems to be defaulted to H2 size and it is just too big.  I tried to omit putting a title but it would not let me, it is required.  I want to be able to change the size of it, to H3 or different and not affect the rest of the site.  This should be able to be stylized like the other details of this.  The images adjust based on the browser however the text stays large.  See attached image.

Please assist if you know of a workaround or css code to change it.

Thanks,

Paul

Add to Home > Design > Custom CSS

h2.ProductItem-relatedProducts-label {
    font-size: 2em;
}

Thank you @tuanphan, it worked great! 😃