but it is right. Two hubs side-by-side, each canted outboard so that a 2-blade rotor sweeps over the other hub, and intermeshes with the othe rotor at 90degrees. Wikipaedia has a picture that helps.
Don't you think the train operators might be p***ed off ...
... when you stop the R-GSM working? So if the twonk with the leaky earbuds turns round and lumps you one when you complain the train staff (yeah well, I know, probability vanishingly small) won't be able to shop him to the BTP.