This is the iCP02 USB PIC Programmer. It connects to your computer via USB and allows you to write programs to PIC microcontrollers. It's used for writing programs to PIC microcontrollers. I bought it new and used it only once to write a program to a PIC microcontroller. It worked without any problems. You connect it to your computer via USB, and then use the programmer to write programs to the PIC microcontroller from your computer. I'm selling it because I no longer use PIC microcontrollers.