BestAir Aprilaire Furnace Humidifier Water Pad, Higher-Output. It measures 14-3/4" in height, 11-1/2" in depth, and 1 1/2" in width. This water pad uses up to 50 percent less water and is treated with micro-free Anti-Microbial coating to protect against contaminants and bacteria. It fits models Aprilaire 112, 136, 224, 440, 445, 445A, 448 (12); Chippewa 224, 225, 226; Humid-Aire Neptune; Walton 600, 620, 660. For best performance, change at least twice per heating season, maybe more depending on water conditions and frequency.

• Fits Aprilaire 112, 136, 224, 440, 445, 445A, 448, & #12.
• 14-3/4 in. in height, 11-1/2 in. in depth and 1 1/2 in. in width.