Patriot Signature Line - DDR3 - module - 4 GB - DIMM 240-pin - 1600 MHz / PC3-12800 - CL11 - 1.5 V - unbuffered - non-ECC
Amazon
Patriot Signature 4GB DDR3 PC3-12800 (1600MHz) CL11 DIMM Memory Module PSD34G160081
Adorama
Patriot Memory Signature Line DDR3 4GB 1600MHz CL11 UDIMM Desktop Memory Module