Hi Jamy,
I have traveled To Canada and the USA with my TENS unit. The only requirement is that you turn it on and I would take a medical document which you that states that you have chronic pain or if it says TENS unit required even better.
You should not have a problem. Best of luck LA and Vegas are pretty close ....perhaps you could come to our So Co meeting on November 3

Teasing! ....Just have lots of fun!!!!
Love and hugs,
Victoria