Class B is opposite to class A in that the current in a specific output flows for one half cycle. In other words, both output devices are never on simultaneously. This system allows for much better efficiency, but displays poor linearity around the crossover region, since it takes time to turn one device off and the other device on. This in turn translates into extreme crossover distortion, thus restricting class B designs to power consumption critical (battery operated) applications, such as two-way radio and other communications audio.