Channel balance left and right

Hi Rick, thanks for writing in. Take a look at our Series 770. You'll need to ascertain the length of the metal channel in order to select the correct option. There should also be a stamp or imprint on the metal channel which will indicate the correct stamp option. Let me know if you have further questions. 

Great. That would make it our S770-29. You'll still need to ascertain the stamp or imprint on the metal channel which tells you what option to select.