This is the E-Flite RS232 Serial Link/Programming Software. This allows you to program your E-flite ESC on your Laptop or PC! Features Works with E-flites 30, 40 and 60 amp Pro Switch-Mode ESC's Overview Programming your ESC will be much faster and easier with the RS232 Serial Link and Programming Software. This will allow you to update your ESC using your laptop or PC. You must have a Serial Port on your computer or you can purchase a separate USB to DB9 adapter (available at computer retailers). Tech Notes Works with the following speed controls: EFLA1060EFLA1040EFLA1040LEFLA1030