The Rinnai condensate collector, model 222053, is designed for use with the Rinnai and Ubbink non-condensing concentric bi-flow vent systems. This essential component connects to the built-in condensate collector of the Rinnai LS, RL, RV, or V Series Tankless Water Heaters.
Condensate Trap for tankless water heater vent pipe.
Looks to be constructed well and works well. If you run your vent in a vertical manner you must drain the condensate to prevent it from draining into the heating unit. This item is the fix for that problem if you do not have an open drain near your tankless water heater.