Providing 30-percent more air velocity than most standard box fans, this 20-inch fan features the Wind Ring system, an exclusive high-performance grill design that focuses the air movement, increasing its velocity. The unit also offers three, whisper-quiet, energy-efficient speeds, as well as a weather-shield motor for worry-free window use. Other highlights include an easy-to-use control knob, a convenient carry handle, a lightweight design, and a wider body for greater stability. Made in the U.S., the UL-listed box fan comes fully assembled