Related products font size

Hello, I want to change the font size of the "related products" title that is shown in the sigle product page (woocommerce). If I change it through "appearance" it will change the size in every title of the site. I just want to change that title. How can I do that? Can you send me the ccs code for that? (I have already managed to change the single product title and price's font size with ccs but can't find the code for "related products": .single-product .product_title{ font-size:28px !important; } ) Thank you for your help!