The Lasko 3720 Performance 20 In, Weather Shield Box Fan features a patented Weather Shield motor for worry-free window use, The control knob has three quiet speed settings and the high-performance grille provides ultimate airflow, The wider body allows for greater floor stability and the convenient handle makes it portable, The patented, fused safety plug provides additional worry-free use, Plus, with the Save-Smart design, this fan costs less than 2-cents per hour to run!, 20 inch box fan with Save-Smart design costs less than 2-cents per hour to run, Patented, isolated Weather Shield motor for worry-free window use, High-performance grille for ultimate airflow, Wider body for grater floor stability, Easy to use control knob with 3 quiet speeds, Lightweight design and convenient carry handle for portability, Patented, fused safety plug, ETL Listed, SKU: ALMO2749