So, Obvious Man here. I will state the obvious. Not all TT's come with a black tank flush system. That is why there are so many cheap portable flush systems for sale. (Most do not work in most situations.)
I have rarely seen a marketing or advertising publication that listed things not included except "batteries not included".
15 years ago very few TT's had a black flush system. Today many do. If you have one, it probably looks just like your city water connector.
Some newbies have mistaken it for a city water connection and over-flowed their black tank, out the roof, out the toilet, out the bathroom sink?
I wish you good luck and happy trails ahead!
I wish you good luck and happy trails ahead!