Amazon.com: HP ProBook 640 G1 Intel i5-4200M 2.50GHz 8GB RAM 128GB SSD Windows 10 Pro (Renewed) : Electronics
HP ProBook 640 G1 14" Intel i5-4300M 2.80GHZ 8GB RAM NO CADDIE,NO HD ,NO OS | eBay
HP Probook 640 G1 Upgrade RAM, SSD, Hard Drive (Disassembly & Replacement) - YouTube
HP ProBook 640 G1 14" Intel Core i5-4200M 2.5GHz / 8GB / 500GB vs HP ProBook 6470b 14" Intel Core i5-3210M 2.5GHz / 4GB / 320GB: What is the difference?
HP ProBook 640 G1 14" 1366x768 - i5-4200M 2.50 GHz Processor, 8GB RAM, 128SSD, Windows 10, Grade B+ - Green Dragon Technology