same thing but fuseable. i got my fingers caught too many times.they have another place where you can lock them out. as you turn it on or off, you can put a padlock through here or some other device. and when you're working on an electrical system, typically, you will lock it out. you will tag it out so that you know that the continuing is turned off and nobody -- thing is turned off and nobody continuation it on. you'll tag it out by put a tag. >> up until now, we have been talking about power wiring, 240 volts. here we are in some air where there is low-vot ago wiring used for communications. >> we have two kinds of wire. we have line voltage and low voltage. what is the difference between those two types. >> the low-voltage wiring doesn't present a shock hazard. you don't have to put the wires in a conduit or a cable. this is thermostat wire. it's called class two wire. when you have a class two transformer, you're allowed to run this cable either exposed or concealed in building construction without a cable. there would be an example of some si