Thrasher ,we used to carry one on all our trucks...sometimes they would be used while pulling an energized meter base...depending on the service center that a lineman worked at ,they sometimes had to wear them while opening an energized urd transformer.....but mostly the rule was if you were in a vault type of set-up,then it was required,that and the leather 480 volt jacket.....the jackets were a different story....yes Ive used one a couple of times and might have seen just a few guys use one......then there were those cold days with high winds.....thats when they were mostly used.