Uh. Hot Tap water heaters are made and marketed in the United States. Not sure what you are asking for...
The rugged all-steel construction of the Zodi™ High Performance Instant Hot Tap HP™ makes it perfect for all season use. The portable double burner shower system heats unlimited water on demand.
zodi.com
I have to assume you are talking about another product called Hot Tap...
I have the single bottle version, have had it since 2005. It works well, but dribbles a tiny bit over the years...
Enjoy the convenience of instant hot showers with matchless push button ignition. The Zodi Hot Tap™ is easy to use to provide comfortable hot showers in seconds.
zodi.com
I find since I am otherwise 100% liquid fuel, I have the battery powered version as well, sort of the same thing without the metal parts, and some extended hose, I made a heat exchanger from a 50' roll of 3/8" tubing, I heat it over my Coleman stove, and use it regularly. I wish they made something similar with a build in liquid fuel burner, but no such luck...
Honestly, my ideal gear list would be everything that runs on any fuel, run on gasoline, and as poor a quality as is around. My big drawback is the heater itself. There are stove top heaters but I am not a fan of open flame inside the tent...