I agree, I remember seeing a mix of saltwater and freshwater equipment on the giveaway table. Take it out if you can't be 100% sure what it's actually made of.
You could put something like this on the outlets of the Delta 2 instead of getting Inkbird and waiting for the temperature to drop.
https://www.amazon.com/Failure-Adjustable-Indicator-Refrigerator-Aquarium/dp/B0CZMGL2D2/?th=1