The IZF21/31 fans offer market-leading performance, functionality, size and accessories. Treat an area up to 2' x 8', neutralizing static as rapidly as 0.5s while achieving a ±5V balance. 8 emitters provide high ion output, and reverse polarity each time power is supplied, increasing durability. Controls include a power switch, 10-speed fan adjuster, and ion balance adjuster. 4 red/green LEDs