Do not waste your money on TriSquare eXRS radios. They ALL have syncing issues...and there is NO way to solve these issues, no matter what the manufacturer says.
I bought 4 pairs several years ago from a distributor at a huge discount. The syncing problems make them completely undependable, they are definitely not to be used in a serious, life or death, or emergency situation. I do use the ones that I have on a daily basis for a home intercom system. I keep a pair in the charger at all times at each location in my home. This doubles the chance of actually being able to receive a transmission, but even with the odds doubled, they fail to sync often.
EDIT: Any reviews on amazon or elsewhere that claim to have no problems with these radios, are assuredly TriSquare plants trying to promote their shitty product.
On a side note, I've heard that the software that these use for their FHSS (frequency hopping spread spectrum), is the exact same software used in Dessert Storm 1 that caused more than one U.S. tank to be destroyed by friendly fire for lack of being able to communicate at critical times.