I was a working maintenance supervisor at a manufacturing company over near you, on McGinnis Ferry Road. We purchased a Major brand name circuit breaker locator. You must read and always follow directions for the desired results. Sometimes, we experienced an erratic read and it would indicate on two or three breakers. We would lock out all breakers (Please use "Lock Out devices, and if it's industrial Tag out as well) That way no one can come by the breaker panel and re-energize a circuit you may be working on.
Please use a voltage detector (Small pocket model, just a bit bigger than a large pen as a final check for voltage present, use the audible & visible mode, available at Lowes and HD. The few dollars spent is well worth it.
Lock Out - Tag Out kits are available for safety equipment suppliers, not only for breakers, light switches, and disconnects (lever).
Short answer NO. I do not see a UL label on it. Long answer why would you want one??? Want to find a circuit in a house use a drill motor or vac. or something you plug in and can hear like a radio. The breakers in your house panel should be labled and if not then start flipping breakers and spend a 1/2 day and mark all breakers properly. Nothing in your house can not be shut off so there is no danger there. In industry they do come into play but even better quality ones are suspect and would not trust. Before working on any circuit even though you believe you found the right breaker you need to check with a voltage tester and even then there can be potential danger. before the latest code a neutral wire can be shared between 2 circuits so that neutral (white wire) may still carry voltage but you will not pick it up with a voltage tester. Get between white wire and path to ground and it will hurt you.
There are no short answer in the electrical world.
Probably a good choice to pass on it Tony. I tried to use one of these several years ago with so so results. If you are tracing circuits in your home just use the on/off method and see what works and what doesn't. A little tester like this one will help with that. Once you have identified what the breaker controls, label it and you never have to worry about it again.
I use one on my circuit panel to identify which circuit breaker will turn off a given receptacle. They are simple to use and can be relatively inexpensive to purchase. You can also purchase accessories like a screw in plug for lights so that you can plug the transmitter into them and figure out which circuit breaker will turn off that light.
I have used other brands and they work good. Just be sure to check for voltage on the line you are working on first before doing any work on it. I have found them to be reliable but there is a human working with it and they do not always work as well.
JT, is spot on about older wire schemes. I was once removing a light fixture in a bathroom in a home with an older wiring setup. I make sure the breaker is off, check to make sure the switch for the light is off as well, removing light fixture and touch white wire and ZZZZap, I was electrified.