Transformers 8V10VA, 16V10VA, 24V20VA - Our Quality Transformers Thermally Protect a number of our devices.Transformers 8V10VA, 16V10VA, 24V20VA features include: Quality Transformers engineered to ensure long life with bells, buzzers, chimes, door openers, etc. 120 VAC Input Thermally Protected Fits Standard Wiring Knockout Class 2 Energy Limiting Type Quick Clamp mounting feature allows quick amp; easy installation UL/CSA Listed Order Qty of 1 = 1 Piece Below is more info on our Transformers 8V10VA, 16V10VA, 24V20VA