ThinkPad R50 1831-xxx 1GB PC2700 DDR Memory for IBM ThinkPad R50 1831-xxx RAM-1Gb 1024MB DDR SODIMM 333MHz PC2700 200pin 2.5v memory upgrade.The latest high density chips which draw less power and run cooler than other brands. This keeps laptop notebook run more stable.It is highly recomended for Apple notebooks Few intel Mobile notebooks and laptops with AMD cpu. Equalant part # DC890B 324702-001 344868-001 KTH-ZD7000/1G 31P9834 and KTT3311/1G and many more.