Is this mixture safe? (RAM)

Hey I built my computer a few years ago with 4 GB (2 modules) of "Sector 5" G Series PC3-10666 1333 MHZ

I'm going to get a new video card tomorrow and figured I would grab the other 4GB while I'm at Microcenter. They no longer have the exact ram but they do have,

"G Series 'Sector 5' edition 4GB DDR3-1600 (PC-12800) CL9 Dual Channel Desktop Memory Kit (Two 2GB Memory Modules)"

Can I combine these two with no ill effects?

Thanks in advance