UL Listed Class 2 Plug-In Electronic Transformers. Combining Class 2 Transformers in a single package creates a single source to wire multiple runs of low voltage fixtures such as under cabinet and display luminaires. UL listed Class 2 plug-in electronic transformers. Plug-in power supply with on-off switch and 6' detachable cord. Class 2 transformers are required for most cabinet listed fixtures. Track Transformer in Black