They are magnetic pulse generators. As stated by Dogdays they create an AC voltage as the tooth from the trigger wheel passes by. I'd be more concerned with that than resistance. Stick one in the dist,connect a voltmeter to the leads,set the scale on ac volts and give the dist a spin. The number I've always been told is 300mv ac minimum. If it makes that it should be enough to trigger the box which in turn controls coil primary current flow.(I'm guessing any of those listed will work) Good luck.