Full Details from Amazon.com : http://www.amazon.com/gp/product/B00005JGD2?tag=onigi-20
Hewlett Packard 82215A 128 KB RAM Card for the HP 48GX
128 KB RAM memory card
Compatible only with the HP 48gx calculator
Powered by its own long-lasting battery
Can be added to the main memory or used as an electronic disk
A quality HP product
