Get relief from hot weather and stale air using the Bionaire Thin Window Fan with Digital Thermostat. Designed to fit windows with minimum openings of 25.5 inches by 8.0 inches. This window fan unit uses three independently controlled fans to circulate air and provide efficient cooling. This window circulator fan comes equipped with an easy-to-operate thermostat dial, and it features three speed settings for personalized comfort. The airflow is fully reversible, allowing for intake of fresh cool air, exhaust of hot, stale air, or exchange for full-room circulation. Dual locking extender screens hold the fan rigidly in place, helping ensure a secure fit. It is more powerful with 40% greater air velocity compared to similar window fans and 25% more compact to reduce window obstruction. With Bionaire brand technology, you can live in harmony with nature for a serene home environment. 3 Speed Settings. Manual Thermostat. Designed for Use Either Horizontally or Vertically. New 'Firm Fit' Locking Extender Screen. COLOR: White. Product Dimensions: 27 x 6.6 x 9.2 inches.