Triad prepackaged wall plug-in power supplies decrease product design time. These plug-in power sources eliminate the need for internal power supply cooling devices, thereby reducing the noise level, size and weight of the end product. In addition, these compact power sources keep heat away from sensitive circuits, and supply a safer lower output to the end product. Wall plug-in sources are completely enclosed to prevent tampering. They are offered in a wide range of popular voltages, power levels and reversed polarity (-R). The output voltage is regulated; which means the output voltage will not vary much with load. Models are available with generous six foot cord lengths. Available in 50-60 Hz operating frequency. Level IV and V efficiency. Meets EIAS 2007 energy efficiency requirements for external power supplies.