The Active Grow 22W T8 High-Output Horticultural Lamp is an LED tube that replaces 32W/40W T8/T12 fluorescent lamps and features 30% higher PPF output, lower power consumption and 100% more effective spectrums for plant growth. The T8 LED Horticultural Lamp has a 190° beam angle for wide light distribution and runs cool, so it can be placed closer to plants and save space. All Active Grow T8 LED tubes work with existing T8 or T12 fluorescent light fixtures by bypassing the ballast and wiring to single-ended power on universal 120-277 voltage. Without the need for a ballast these lamps do not flicker, buzz or experience longevity issues. T8 fixtures require non-shunted lamp holders (tombstones) and are non-dimmable.