HIGH-QUALITY TRANSFORMER FOR DOORBELL: 8-volt, 20VA or 16-volt, 20VA transformer for use with multiple door chimes in one home SAFE AND RELIABLE: cULus Listed for safety, ensuring you have a quality, reliable transformer that will pass inspection and a thermal cut-off switch designed to shut off the door chime system in the event of excessive temperature DURABLE CONSTRUCTION: Constructed of high-quality materials to ensure lasting use EASY INSTALLATION: Transformer features an easy-to-install lock-mount or wall-mount that reduces installation time by 25% IDEAL SIZE: Transformer measures 2.015" x 1.906" x 2.53", making it the perfect size for your door chime