This ingenious solar air heater is the perfect way to keep rooms nice & warm without running up your home heating bill. Just place it in a south-facing window and let it go to work. It's solar-powered fan draws cool room air in where it's heated by a grid of sun-heated solar collectors and recirculated back into the room. Without costing you a penny in electricity charges! Supplied hardware. Ideal as supplementary heat or for heating small spaces up to 150 sq. ft. Recommended for single pane windows only. 47"L x 19"W x 2"D.