Since light is the most important single factor affecting your plant's life cycle - a quality light meter is an essential tool in accurately determining if your crop is receiving the maximum light needed for healthy growth. A light meter allows growers an accurate means of adapting to their plant's needs as the light conditions change during a full growing season. The Active Eye Analogue Light Meter identifies the best light level of healthy plants and has an easy-to-use hand-held design. You can get precise readings with two scales and it has a lifetime silicon sensor and so no batteries are required. The meter can read up to 270000 lux of sun or high intensity or fluorescent light. It also has an exclusive "Zero" calibration feature (accurate to 2%).