4GB DDR3-1600 LOW VOLTAGE UDIMM - AX31600N11Z/4LAxiom Memory Axiom 4GB DDR3L 1600 Low Voltage UDIMM AX31600N11Z 4L 4 GB DDR3 1600 PC3L 12800 DDR3 SDRAM 1600 MHz 1. 35 V Non ECC Unbuffered 240 pin UDIMM Lifetime Warranty VPN: AX31600N11Z 4L SKU: RSC137883 UPC: 841280113901 UDIMM 4 GB memory allows you to have more programs open at a time 1600 MHz memory speed with Unbuffered signal for great multitasking capability 240 pin pin DDR3 SDRAM interface multiplexes 2 bit data from memory cell and I O