8GB 2X4GB Memory RAM for HP ProBook 4420s 204pin 1333MHz PC3-10600 DDR3 SO-DIMM Black Diamond Memory Module Upgrade - Walmart.com
Laptop Motherboard For Hp Probook 4530s 4730s Hd5470 Pc Mainboard 658343-001 658343-501 6050a2465501-mb-a02 Full Tesed Ddr3 - Motherboards - AliExpress
A-Tech 8GB KIT (2 x 4GB) For HP-Compaq ProBook Series 4230s 4330s 4331s 4430s
CMS 8GB (2X4GB) DDR3 10600 1333MHZ Non ECC SODIMM Memory Ram Upgrade Compatible with HP/Compaq® Probook 4535S, 4710S, 4720S, 4730S, 5220M, 5310M - A29 at Amazon.com