I return, with a new lock! There was no exact one but the diameter is correct, it just sticks out a small tad but is neat enough. Though I can't work out were the wires should go and were the 3 hole plug goes (I presume it's behind the LED power plugs so thats what I used at the time). I tried to hold the wires on by my finger and switching the machine on and no luck. It always turns on. Some sort of diagram would be great here. :-?