Will it work with Koss model C220 home theater system. It's a old unit

Hello Valued Customer, thank you for your question. We would love to be able to provide you with a definitive answer before you purchase the remote, but this is not possible. We do have one code for Koss Home Theater systems, so it is certainly possible that it can work. We would also be more than happy to walk you through the programming process over the phone to ensure that everything is being done correctly. If you have any further questions, please don’t hesitate to respond or give us a call between the hours of 7:00 AM – 8:00 PM Central Standard Time, Monday thru Friday at 1-800-654-8483, and press option 4. Please refer to your ticket number (595946) if you decide to give us a call. Thank you.