Example: SLN12020-4.5S-1
 A solar water heater with 120 gallon storage capacity and a 20 square foot heat exchanger coil with a single 4.5 KW back-up electric heating element rated at 240 volt 1 phase.

Option Note
Any and all optional equipment for a water heater must be called out in the written specifications. A model number in and of itself does not reflect any optional equipment selected.