The Hydrofarm LG17010 light meter is the tool growers need to achieve the results they want by measuring the quality of light their plants are receiving. With its easy to use hand-held design, the meter measures grow lights or sunlight, up to 5,000 footcandles, giving you precise readings on three scales. This precision instrument is fully cosine corrected for the angular incidence of light, meaning that even if the sensor isn't held perfectly perpendicular to the light source, the meter still reads the light correctly. The meter features a built-in low battery indicator, assuring you'll never be caught with a low-power product. Includes informative booklet with lighting recommendations and carrying case.