Photo 4 for Bestway Lay-Z-Spa Pump/heater #13804 Coleman Inflatable Hot Tub Heater 110-120V

I've been looking for a Laz-y-Spa Airjet pump/heater for some time. It appears there are many models, all similar, with just minor differences. Your model is the only one I've seen with a t-connector on the input line. What is the purpose of the T? How did ithe 2 input lines connect to the spa? Thank you, Paul Williams