for virtually any roof type featuring gable-end architecture or retrofit ventilation applications. With our versatile design,The Zephyr GM series fans offer easy installation behind... or underneath any properly sized passive vent or louvered gable vent. The Zephyr GM model series is a great alternative for customers who want the benefits of solar powered ventilation... without the need for making a roof penetration. The Zephyr AB-255 Price: $599.99 The Zephyr AB-205 Price: $509.99 ...