Hp 4gb ddr3l 1600 135v sodimm laptop memory specifications general capacity 4 gb upgrade type system specific memory type dram technology ddr3l sdram form factor so dimm 204 pin speed 1600 mhz pc3 12800 data integrity check non ecc features unbuffered voltage 135 v compatibility information designed for hp 250 g4 hp elitebook 2170p 2560p 2760p 725 g2 745 g2 755 g2 820 g1 820 g2 840 g1 840 g2 8460p 8460w 8470p 8470w 850 g1