For older sound base systems, if you look at the rear of the ZVOX system you will see the model printed on the back panel for example 555, 570,770. 

If you own the ZVOX Sound bar systems you will see the serial number on the back or bottom panel. The model number is the first three digits, for example 157, 203, 155 or 380.

ST157 6540654 1233

Please call 866-367-9869 for assistance.