toyota corolla wiring diagram

Hello to all, I want to thank all of you in advance for all the help. This is my first posting. I have a 1993 Toyota Corolla with a aftermarket CD player. I saw a Toyota Corolla Cd Mp3 Radio Player 09 10 11 Sat Stereo on Ebay. The stereo does not have the connector (female). Right side on the back has a set of male plug and I know this is for power, memory, left and right speaker, etc. On the left side, there is a set of male plug but the pins are smaller. Can someone tell me what is this plug for. The head unit is has a internal amplify. Here is the link: http://the12volt/ws/eBayISAPI.dll?ViewItem&item=360369987295&ssPageName=STRK:MEWAX:IT Thanks for all the advices.

Why do you want to go back with another factory radio? Factory is never going to be the same quality as a nice aftermarket. Save yourself some time and go get a nice Kenwood or Alpine. You will be much happier with the featurs and the sound quality, and as much as they normaly want for the factory radios you probably wont be to far off on the price.