From a comment below the article:

"I debunk the flamethrower...

it's just a Push-Start Propane Blow Torch ( 50$ from Amazon ) mounted in S.T.A.R. XR-5 Airsoft ( 112$ ). Start piezo button is inverted and in the hole with finger.

You can see the propane valve button on top of the gun... and you have a propane torch able to burn grass in your garden .. "

See https://www.amazon.com/Push-Start-Propane-Blow-Torch-Long/dp...

Musk gets $600 for a piece of kit worth around $75 and the fan-bois lap it up.