This is a high quality serial cable with molded connectors for the HP48 series calculators. It will allow you to load your programs from your computer to your calculator. The HP48G Serial Cable comes standard with a DB9 connector for any computer equipped with a standard serial port (COM Port). The other cable end comes with the 4 pin HP48 Series Connector - please refer to images for more details. Link software is available on the internet for free.