According to a guy on the Freeballer forum it's Levi #514 and #511.
In fact- here is his post:
"Hi, you should check out the new Levi styles. #514 and #511 are mens jeans what are low and snug. I tried on the 511's, and they are as form fitting as a pair of running tights. So, manufacturers are starting to make jeans that are tight again, and I bet they would be great for the freeballin crowd. Nice to know that guys are trying to show off their bodies instead of hiding them."