HOTTAP Go runs on standard 1lb propane canisters. Each canister heats up to 90L/24gal of water to shower temperature. That’s roughly 15 showers

The HOTTAP Go also works with 9kg/20lbs standard BBQ gas tanks - you’ll just need a compatible hose and regulator to suit.

Does it run on natural gas? 

Both the HOTTAP and HOTTAP Go do not run on natural gas.