The Philly Roller Girls are currently known as Philly Roller Derby. 

A virtually identical patch is already posted for Philly Roller Girls, but a close examination reveals they're not the same thing.  The first difference is the color.  This is a deeper blue than the other. That could be more a matter of lighting in the photo though.  The real proof is in the size of the bell/skate.  In this patch it's entirely surrounded by white.  In the other patch it's done a bit larger and bleeds significantly into the outer blue ring.  This was definitely not a simple error of production.  Also, the lace holes are filled in on this design.  On the other they're hollow circles.