css target trouble on my product sku

hi. I am trying to target a specific span on my site so I can set the display to none, but I'm having trouble getting it targeted and affectd.

Here's my site: http://politicalshop.dev.tilpropreview.com/

basically, on the home page it is displaying the SKU numbers under the price and I want to hide them, but I'm not having any luck.

A screen shot is attached. I've tried to target using:

.product_sku{display:none!important;}

but the SKU's do not hide. what should I try?

thanks,