This Smart Controller contains a SD-Card reader, an rotary encoder and a 128x64 LCD display. You can easy connect it to your Ramps board using the "smart adapter" included. After connecting this panel to your Ramps you don't need your pc any more, the Smart Controller supplies power for your SD card. Further more, all actions like calibration, axes movements can be done by just using the rotary encoder on the Smart Controller. Print your 3D designs without PC, just with a g-code design stored on the SD card.
Compares to the 2004 Smart LCD Controller With Adapter, this 128x64 screen can display much more information, which would help for you run the 3D printer without a computer.