Tank has a 1 inch hole in the back. Appears to be for a pluggin. Nothing included. Cannot use. Reached out to Orion, and it appears that I've accidentally bought the wrong tank for the streetlegal version (which I don't have). The hole is meant for the fuel level sensor (floater).
We discuused the matter, and the guys from Orion made me a fair offer for the correct tank, and they gave me some rebate on the tank and the cap for free with the new tank.
Unfortunately, sending the tank back from the US is more expensive than the tank itself (or one could also say: the tank is too cheap).
Anyway, after the first disappointment I'm now looking forward to receive a good plastic tank which is better than the iron one I have now.

Rating: [5 of 5 Stars!]